diff --git a/beacon_node/beacon_chain/src/data_availability_checker.rs b/beacon_node/beacon_chain/src/data_availability_checker.rs
index ad0e812cf..21cac9a26 100644
--- a/beacon_node/beacon_chain/src/data_availability_checker.rs
+++ b/beacon_node/beacon_chain/src/data_availability_checker.rs
@@ -22,7 +22,6 @@ use std::sync::Arc;
 use task_executor::TaskExecutor;
 use types::beacon_block_body::{KzgCommitmentOpts, KzgCommitments};
 use types::blob_sidecar::{BlobIdentifier, BlobSidecar, FixedBlobSidecarList};
-use types::consts::deneb::MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS;
 use types::{BlobSidecarList, ChainSpec, Epoch, EthSpec, Hash256, SignedBeaconBlock, Slot};
 
 mod availability_view;
@@ -424,7 +423,8 @@ impl<T: BeaconChainTypes> DataAvailabilityChecker<T> {
                 .map(|current_epoch| {
                     std::cmp::max(
                         fork_epoch,
-                        current_epoch.saturating_sub(MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS),
+                        current_epoch
+                            .saturating_sub(self.spec.min_epochs_for_blob_sidecars_requests),
                     )
                 })
         })
@@ -517,7 +517,8 @@ async fn availability_cache_maintenance_service<T: BeaconChainTypes>(
                 let cutoff_epoch = std::cmp::max(
                     finalized_epoch + 1,
                     std::cmp::max(
-                        current_epoch.saturating_sub(MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS),
+                        current_epoch
+                            .saturating_sub(chain.spec.min_epochs_for_blob_sidecars_requests),
                         deneb_fork_epoch,
                     ),
                 );
diff --git a/beacon_node/beacon_processor/src/lib.rs b/beacon_node/beacon_processor/src/lib.rs
index 79b46f90a..045b06a1e 100644
--- a/beacon_node/beacon_processor/src/lib.rs
+++ b/beacon_node/beacon_processor/src/lib.rs
@@ -60,7 +60,6 @@ use std::time::Duration;
 use task_executor::TaskExecutor;
 use tokio::sync::mpsc;
 use tokio::sync::mpsc::error::TrySendError;
-use types::consts::deneb::MAX_BLOBS_PER_BLOCK;
 use types::{Attestation, Hash256, SignedAggregateAndProof, SubnetId};
 use types::{EthSpec, Slot};
 use work_reprocessing_queue::IgnoredRpcBlock;
@@ -168,8 +167,7 @@ const MAX_BLOCKS_BY_RANGE_QUEUE_LEN: usize = 1_024;
 
 /// The maximum number of queued `BlobsByRangeRequest` objects received from the network RPC that
 /// will be stored before we start dropping them.
-const MAX_BLOBS_BY_RANGE_QUEUE_LEN: usize =
-    MAX_BLOCKS_BY_RANGE_QUEUE_LEN * MAX_BLOBS_PER_BLOCK as usize;
+const MAX_BLOBS_BY_RANGE_QUEUE_LEN: usize = 1024;
 
 /// The maximum number of queued `BlocksByRootRequest` objects received from the network RPC that
 /// will be stored before we start dropping them.
diff --git a/beacon_node/lighthouse_network/src/rpc/codec/base.rs b/beacon_node/lighthouse_network/src/rpc/codec/base.rs
index 6d622fcc8..4085ac17b 100644
--- a/beacon_node/lighthouse_network/src/rpc/codec/base.rs
+++ b/beacon_node/lighthouse_network/src/rpc/codec/base.rs
@@ -316,7 +316,7 @@ mod tests {
         ));
 
         // Request limits
-        let limit = protocol_id.rpc_request_limits();
+        let limit = protocol_id.rpc_request_limits(&fork_context.spec);
         let mut max = encode_len(limit.max + 1);
         let mut codec = SSZSnappyOutboundCodec::<Spec>::new(
             protocol_id.clone(),
diff --git a/beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs b/beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs
index 787c3dcb7..7a7f2969f 100644
--- a/beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs
+++ b/beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs
@@ -15,10 +15,11 @@ use std::io::{Read, Write};
 use std::marker::PhantomData;
 use std::sync::Arc;
 use tokio_util::codec::{Decoder, Encoder};
+use types::ChainSpec;
 use types::{
-    BlobSidecar, EthSpec, ForkContext, ForkName, Hash256, LightClientBootstrap, SignedBeaconBlock,
-    SignedBeaconBlockAltair, SignedBeaconBlockBase, SignedBeaconBlockCapella,
-    SignedBeaconBlockDeneb, SignedBeaconBlockMerge,
+    BlobSidecar, EthSpec, ForkContext, ForkName, Hash256, LightClientBootstrap,
+    RuntimeVariableList, SignedBeaconBlock, SignedBeaconBlockAltair, SignedBeaconBlockBase,
+    SignedBeaconBlockCapella, SignedBeaconBlockDeneb, SignedBeaconBlockMerge,
 };
 use unsigned_varint::codec::Uvi;
 
@@ -140,7 +141,7 @@ impl<TSpec: EthSpec> Decoder for SSZSnappyInboundCodec<TSpec> {
 
         // Should not attempt to decode rpc chunks with `length > max_packet_size` or not within bounds of
         // packet size for ssz container corresponding to `self.protocol`.
-        let ssz_limits = self.protocol.rpc_request_limits();
+        let ssz_limits = self.protocol.rpc_request_limits(&self.fork_context.spec);
         if ssz_limits.is_out_of_bounds(length, self.max_packet_size) {
             return Err(RPCError::InvalidData(format!(
                 "RPC request length for protocol {:?} is out of bounds, length {}",
@@ -161,7 +162,11 @@ impl<TSpec: EthSpec> Decoder for SSZSnappyInboundCodec<TSpec> {
                 let n = reader.get_ref().get_ref().position();
                 self.len = None;
                 let _read_bytes = src.split_to(n as usize);
-                handle_rpc_request(self.protocol.versioned_protocol, &decoded_buffer)
+                handle_rpc_request(
+                    self.protocol.versioned_protocol,
+                    &decoded_buffer,
+                    &self.fork_context.spec,
+                )
             }
             Err(e) => handle_error(e, reader.get_ref().get_ref().position(), max_compressed_len),
         }
@@ -451,6 +456,7 @@ fn handle_length(
 fn handle_rpc_request<T: EthSpec>(
     versioned_protocol: SupportedProtocol,
     decoded_buffer: &[u8],
+    spec: &ChainSpec,
 ) -> Result<Option<InboundRequest<T>>, RPCError> {
     match versioned_protocol {
         SupportedProtocol::StatusV1 => Ok(Some(InboundRequest::Status(
@@ -467,12 +473,18 @@ fn handle_rpc_request<T: EthSpec>(
         ))),
         SupportedProtocol::BlocksByRootV2 => Ok(Some(InboundRequest::BlocksByRoot(
             BlocksByRootRequest::V2(BlocksByRootRequestV2 {
-                block_roots: VariableList::from_ssz_bytes(decoded_buffer)?,
+                block_roots: RuntimeVariableList::from_ssz_bytes(
+                    decoded_buffer,
+                    spec.max_request_blocks as usize,
+                )?,
             }),
         ))),
         SupportedProtocol::BlocksByRootV1 => Ok(Some(InboundRequest::BlocksByRoot(
             BlocksByRootRequest::V1(BlocksByRootRequestV1 {
-                block_roots: VariableList::from_ssz_bytes(decoded_buffer)?,
+                block_roots: RuntimeVariableList::from_ssz_bytes(
+                    decoded_buffer,
+                    spec.max_request_blocks as usize,
+                )?,
             }),
         ))),
         SupportedProtocol::BlobsByRangeV1 => Ok(Some(InboundRequest::BlobsByRange(
@@ -480,7 +492,10 @@ fn handle_rpc_request<T: EthSpec>(
         ))),
         SupportedProtocol::BlobsByRootV1 => {
             Ok(Some(InboundRequest::BlobsByRoot(BlobsByRootRequest {
-                blob_ids: VariableList::from_ssz_bytes(decoded_buffer)?,
+                blob_ids: RuntimeVariableList::from_ssz_bytes(
+                    decoded_buffer,
+                    spec.max_request_blob_sidecars as usize,
+                )?,
             })))
         }
         SupportedProtocol::PingV1 => Ok(Some(InboundRequest::Ping(Ping {
@@ -773,21 +788,22 @@ mod tests {
         }
     }
 
-    fn bbroot_request_v1() -> BlocksByRootRequest {
-        BlocksByRootRequest::new_v1(vec![Hash256::zero()].into())
+    fn bbroot_request_v1(spec: &ChainSpec) -> BlocksByRootRequest {
+        BlocksByRootRequest::new_v1(vec![Hash256::zero()], spec)
     }
 
-    fn bbroot_request_v2() -> BlocksByRootRequest {
-        BlocksByRootRequest::new(vec![Hash256::zero()].into())
+    fn bbroot_request_v2(spec: &ChainSpec) -> BlocksByRootRequest {
+        BlocksByRootRequest::new(vec![Hash256::zero()], spec)
     }
 
-    fn blbroot_request() -> BlobsByRootRequest {
-        BlobsByRootRequest {
-            blob_ids: VariableList::from(vec![BlobIdentifier {
+    fn blbroot_request(spec: &ChainSpec) -> BlobsByRootRequest {
+        BlobsByRootRequest::new(
+            vec![BlobIdentifier {
                 block_root: Hash256::zero(),
                 index: 0,
-            }]),
-        }
+            }],
+            spec,
+        )
     }
 
     fn ping_message() -> Ping {
@@ -1391,22 +1407,22 @@ mod tests {
 
     #[test]
     fn test_encode_then_decode_request() {
+        let chain_spec = Spec::default_spec();
+
         let requests: &[OutboundRequest<Spec>] = &[
             OutboundRequest::Ping(ping_message()),
             OutboundRequest::Status(status_message()),
             OutboundRequest::Goodbye(GoodbyeReason::Fault),
             OutboundRequest::BlocksByRange(bbrange_request_v1()),
             OutboundRequest::BlocksByRange(bbrange_request_v2()),
-            OutboundRequest::BlocksByRoot(bbroot_request_v1()),
-            OutboundRequest::BlocksByRoot(bbroot_request_v2()),
+            OutboundRequest::BlocksByRoot(bbroot_request_v1(&chain_spec)),
+            OutboundRequest::BlocksByRoot(bbroot_request_v2(&chain_spec)),
             OutboundRequest::MetaData(MetadataRequest::new_v1()),
             OutboundRequest::BlobsByRange(blbrange_request()),
-            OutboundRequest::BlobsByRoot(blbroot_request()),
+            OutboundRequest::BlobsByRoot(blbroot_request(&chain_spec)),
             OutboundRequest::MetaData(MetadataRequest::new_v2()),
         ];
 
-        let chain_spec = Spec::default_spec();
-
         for req in requests.iter() {
             for fork_name in ForkName::list_all() {
                 encode_then_decode_request(req.clone(), fork_name, &chain_spec);
diff --git a/beacon_node/lighthouse_network/src/rpc/config.rs b/beacon_node/lighthouse_network/src/rpc/config.rs
index ad9673114..989514919 100644
--- a/beacon_node/lighthouse_network/src/rpc/config.rs
+++ b/beacon_node/lighthouse_network/src/rpc/config.rs
@@ -4,7 +4,7 @@ use std::{
     time::Duration,
 };
 
-use super::{methods, rate_limiter::Quota, Protocol};
+use super::{rate_limiter::Quota, Protocol};
 
 use serde::{Deserialize, Serialize};
 
@@ -99,11 +99,9 @@ impl RateLimiterConfig {
     pub const DEFAULT_META_DATA_QUOTA: Quota = Quota::n_every(2, 5);
     pub const DEFAULT_STATUS_QUOTA: Quota = Quota::n_every(5, 15);
     pub const DEFAULT_GOODBYE_QUOTA: Quota = Quota::one_every(10);
-    pub const DEFAULT_BLOCKS_BY_RANGE_QUOTA: Quota =
-        Quota::n_every(methods::MAX_REQUEST_BLOCKS, 10);
+    pub const DEFAULT_BLOCKS_BY_RANGE_QUOTA: Quota = Quota::n_every(1024, 10);
     pub const DEFAULT_BLOCKS_BY_ROOT_QUOTA: Quota = Quota::n_every(128, 10);
-    pub const DEFAULT_BLOBS_BY_RANGE_QUOTA: Quota =
-        Quota::n_every(methods::MAX_REQUEST_BLOB_SIDECARS, 10);
+    pub const DEFAULT_BLOBS_BY_RANGE_QUOTA: Quota = Quota::n_every(768, 10);
     pub const DEFAULT_BLOBS_BY_ROOT_QUOTA: Quota = Quota::n_every(128, 10);
     pub const DEFAULT_LIGHT_CLIENT_BOOTSTRAP_QUOTA: Quota = Quota::one_every(10);
 }
diff --git a/beacon_node/lighthouse_network/src/rpc/methods.rs b/beacon_node/lighthouse_network/src/rpc/methods.rs
index 9a6ad19ac..04ec6bac4 100644
--- a/beacon_node/lighthouse_network/src/rpc/methods.rs
+++ b/beacon_node/lighthouse_network/src/rpc/methods.rs
@@ -5,36 +5,22 @@ use regex::bytes::Regex;
 use serde::Serialize;
 use ssz::Encode;
 use ssz_derive::{Decode, Encode};
-use ssz_types::{
-    typenum::{U1024, U128, U256, U768},
-    VariableList,
-};
+use ssz_types::{typenum::U256, VariableList};
 use std::marker::PhantomData;
 use std::ops::Deref;
 use std::sync::Arc;
 use strum::IntoStaticStr;
 use superstruct::superstruct;
 use types::blob_sidecar::BlobIdentifier;
-use types::consts::deneb::MAX_BLOBS_PER_BLOCK;
 use types::{
-    blob_sidecar::BlobSidecar, Epoch, EthSpec, Hash256, LightClientBootstrap, SignedBeaconBlock,
-    Slot,
+    blob_sidecar::BlobSidecar, ChainSpec, Epoch, EthSpec, Hash256, LightClientBootstrap,
+    RuntimeVariableList, SignedBeaconBlock, Slot,
 };
 
-/// Maximum number of blocks in a single request.
-pub type MaxRequestBlocks = U1024;
-pub const MAX_REQUEST_BLOCKS: u64 = 1024;
-
 /// Maximum length of error message.
 pub type MaxErrorLen = U256;
 pub const MAX_ERROR_LEN: u64 = 256;
 
-pub type MaxRequestBlocksDeneb = U128;
-pub const MAX_REQUEST_BLOCKS_DENEB: u64 = 128;
-
-pub type MaxRequestBlobSidecars = U768;
-pub const MAX_REQUEST_BLOB_SIDECARS: u64 = MAX_REQUEST_BLOCKS_DENEB * MAX_BLOBS_PER_BLOCK;
-
 /// Wrapper over SSZ List to represent error message in rpc responses.
 #[derive(Debug, Clone)]
 pub struct ErrorType(pub VariableList<u8, MaxErrorLen>);
@@ -344,22 +330,23 @@ impl OldBlocksByRangeRequest {
 }
 
 /// Request a number of beacon block bodies from a peer.
-#[superstruct(
-    variants(V1, V2),
-    variant_attributes(derive(Encode, Decode, Clone, Debug, PartialEq))
-)]
+#[superstruct(variants(V1, V2), variant_attributes(derive(Clone, Debug, PartialEq)))]
 #[derive(Clone, Debug, PartialEq)]
 pub struct BlocksByRootRequest {
     /// The list of beacon block bodies being requested.
-    pub block_roots: VariableList<Hash256, MaxRequestBlocks>,
+    pub block_roots: RuntimeVariableList<Hash256>,
 }
 
 impl BlocksByRootRequest {
-    pub fn new(block_roots: VariableList<Hash256, MaxRequestBlocks>) -> Self {
+    pub fn new(block_roots: Vec<Hash256>, spec: &ChainSpec) -> Self {
+        let block_roots =
+            RuntimeVariableList::from_vec(block_roots, spec.max_request_blocks as usize);
         Self::V2(BlocksByRootRequestV2 { block_roots })
     }
 
-    pub fn new_v1(block_roots: VariableList<Hash256, MaxRequestBlocks>) -> Self {
+    pub fn new_v1(block_roots: Vec<Hash256>, spec: &ChainSpec) -> Self {
+        let block_roots =
+            RuntimeVariableList::from_vec(block_roots, spec.max_request_blocks as usize);
         Self::V1(BlocksByRootRequestV1 { block_roots })
     }
 }
@@ -368,7 +355,15 @@ impl BlocksByRootRequest {
 #[derive(Clone, Debug, PartialEq)]
 pub struct BlobsByRootRequest {
     /// The list of beacon block roots being requested.
-    pub blob_ids: VariableList<BlobIdentifier, MaxRequestBlobSidecars>,
+    pub blob_ids: RuntimeVariableList<BlobIdentifier>,
+}
+
+impl BlobsByRootRequest {
+    pub fn new(blob_ids: Vec<BlobIdentifier>, spec: &ChainSpec) -> Self {
+        let blob_ids =
+            RuntimeVariableList::from_vec(blob_ids, spec.max_request_blob_sidecars as usize);
+        Self { blob_ids }
+    }
 }
 
 /* RPC Handling and Grouping */
diff --git a/beacon_node/lighthouse_network/src/rpc/mod.rs b/beacon_node/lighthouse_network/src/rpc/mod.rs
index d6686ff1b..277d04c3b 100644
--- a/beacon_node/lighthouse_network/src/rpc/mod.rs
+++ b/beacon_node/lighthouse_network/src/rpc/mod.rs
@@ -26,7 +26,7 @@ pub(crate) use protocol::InboundRequest;
 pub use handler::SubstreamId;
 pub use methods::{
     BlocksByRangeRequest, BlocksByRootRequest, GoodbyeReason, LightClientBootstrapRequest,
-    MaxRequestBlocks, RPCResponseErrorCode, ResponseTermination, StatusMessage, MAX_REQUEST_BLOCKS,
+    RPCResponseErrorCode, ResponseTermination, StatusMessage,
 };
 pub(crate) use outbound::OutboundRequest;
 pub use protocol::{max_rpc_size, Protocol, RPCError};
diff --git a/beacon_node/lighthouse_network/src/rpc/protocol.rs b/beacon_node/lighthouse_network/src/rpc/protocol.rs
index 95fdc2083..9c174b8e4 100644
--- a/beacon_node/lighthouse_network/src/rpc/protocol.rs
+++ b/beacon_node/lighthouse_network/src/rpc/protocol.rs
@@ -2,7 +2,6 @@ use super::methods::*;
 use crate::rpc::{
     codec::{base::BaseInboundCodec, ssz_snappy::SSZSnappyInboundCodec, InboundCodec},
     methods::{MaxErrorLen, ResponseTermination, MAX_ERROR_LEN},
-    MaxRequestBlocks, MAX_REQUEST_BLOCKS,
 };
 use futures::future::BoxFuture;
 use futures::prelude::{AsyncRead, AsyncWrite};
@@ -22,7 +21,7 @@ use tokio_util::{
 };
 use types::{
     BeaconBlock, BeaconBlockAltair, BeaconBlockBase, BeaconBlockCapella, BeaconBlockMerge,
-    BlobSidecar, EmptyBlock, EthSpec, ForkContext, ForkName, Hash256, MainnetEthSpec, Signature,
+    BlobSidecar, ChainSpec, EmptyBlock, EthSpec, ForkContext, ForkName, MainnetEthSpec, Signature,
     SignedBeaconBlock,
 };
 
@@ -89,32 +88,6 @@ lazy_static! {
     + (<types::KzgCommitment as Encode>::ssz_fixed_len() * <MainnetEthSpec>::max_blobs_per_block())
     + ssz::BYTES_PER_LENGTH_OFFSET; // Length offset for the blob commitments field.
 
-    pub static ref BLOCKS_BY_ROOT_REQUEST_MIN: usize =
-        VariableList::<Hash256, MaxRequestBlocks>::from(Vec::<Hash256>::new())
-    .as_ssz_bytes()
-    .len();
-    pub static ref BLOCKS_BY_ROOT_REQUEST_MAX: usize =
-        VariableList::<Hash256, MaxRequestBlocks>::from(vec![
-            Hash256::zero();
-            MAX_REQUEST_BLOCKS
-                as usize
-        ])
-    .as_ssz_bytes()
-    .len();
-
-    pub static ref BLOBS_BY_ROOT_REQUEST_MIN: usize =
-        VariableList::<Hash256, MaxRequestBlobSidecars>::from(Vec::<Hash256>::new())
-    .as_ssz_bytes()
-    .len();
-    pub static ref BLOBS_BY_ROOT_REQUEST_MAX: usize =
-        VariableList::<Hash256, MaxRequestBlobSidecars>::from(vec![
-            Hash256::zero();
-            MAX_REQUEST_BLOB_SIDECARS
-                as usize
-        ])
-    .as_ssz_bytes()
-    .len();
-
     pub static ref ERROR_TYPE_MIN: usize =
         VariableList::<u8, MaxErrorLen>::from(Vec::<u8>::new())
     .as_ssz_bytes()
@@ -375,7 +348,7 @@ impl AsRef<str> for ProtocolId {
 
 impl ProtocolId {
     /// Returns min and max size for messages of given protocol id requests.
-    pub fn rpc_request_limits(&self) -> RpcLimits {
+    pub fn rpc_request_limits(&self, spec: &ChainSpec) -> RpcLimits {
         match self.versioned_protocol.protocol() {
             Protocol::Status => RpcLimits::new(
                 <StatusMessage as Encode>::ssz_fixed_len(),
@@ -390,16 +363,12 @@ impl ProtocolId {
                 <OldBlocksByRangeRequestV2 as Encode>::ssz_fixed_len(),
                 <OldBlocksByRangeRequestV2 as Encode>::ssz_fixed_len(),
             ),
-            Protocol::BlocksByRoot => {
-                RpcLimits::new(*BLOCKS_BY_ROOT_REQUEST_MIN, *BLOCKS_BY_ROOT_REQUEST_MAX)
-            }
+            Protocol::BlocksByRoot => RpcLimits::new(0, spec.max_blocks_by_root_request),
             Protocol::BlobsByRange => RpcLimits::new(
                 <BlobsByRangeRequest as Encode>::ssz_fixed_len(),
                 <BlobsByRangeRequest as Encode>::ssz_fixed_len(),
             ),
-            Protocol::BlobsByRoot => {
-                RpcLimits::new(*BLOBS_BY_ROOT_REQUEST_MIN, *BLOBS_BY_ROOT_REQUEST_MAX)
-            }
+            Protocol::BlobsByRoot => RpcLimits::new(0, spec.max_blobs_by_root_request),
             Protocol::Ping => RpcLimits::new(
                 <Ping as Encode>::ssz_fixed_len(),
                 <Ping as Encode>::ssz_fixed_len(),
diff --git a/beacon_node/lighthouse_network/src/service/mod.rs b/beacon_node/lighthouse_network/src/service/mod.rs
index d15bde37d..812c33716 100644
--- a/beacon_node/lighthouse_network/src/service/mod.rs
+++ b/beacon_node/lighthouse_network/src/service/mod.rs
@@ -41,8 +41,7 @@ use std::{
 };
 use types::ForkName;
 use types::{
-    consts::altair::SYNC_COMMITTEE_SUBNET_COUNT, consts::deneb::BLOB_SIDECAR_SUBNET_COUNT,
-    EnrForkId, EthSpec, ForkContext, Slot, SubnetId,
+    consts::altair::SYNC_COMMITTEE_SUBNET_COUNT, EnrForkId, EthSpec, ForkContext, Slot, SubnetId,
 };
 use utils::{build_transport, strip_peer_id, Context as ServiceContext, MAX_CONNECTIONS_PER_PEER};
 
@@ -226,7 +225,7 @@ impl<AppReqId: ReqId, TSpec: EthSpec> Network<AppReqId, TSpec> {
 
             let max_topics = ctx.chain_spec.attestation_subnet_count as usize
                 + SYNC_COMMITTEE_SUBNET_COUNT as usize
-                + BLOB_SIDECAR_SUBNET_COUNT as usize
+                + ctx.chain_spec.blob_sidecar_subnet_count as usize
                 + BASE_CORE_TOPICS.len()
                 + ALTAIR_CORE_TOPICS.len()
                 + CAPELLA_CORE_TOPICS.len()
@@ -239,7 +238,7 @@ impl<AppReqId: ReqId, TSpec: EthSpec> Network<AppReqId, TSpec> {
                     possible_fork_digests,
                     ctx.chain_spec.attestation_subnet_count,
                     SYNC_COMMITTEE_SUBNET_COUNT,
-                    BLOB_SIDECAR_SUBNET_COUNT,
+                    ctx.chain_spec.blob_sidecar_subnet_count,
                 ),
                 // during a fork we subscribe to both the old and new topics
                 max_subscribed_topics: max_topics * 4,
@@ -639,7 +638,7 @@ impl<AppReqId: ReqId, TSpec: EthSpec> Network<AppReqId, TSpec> {
         }
 
         // Subscribe to core topics for the new fork
-        for kind in fork_core_topics::<TSpec>(&new_fork) {
+        for kind in fork_core_topics::<TSpec>(&new_fork, &self.fork_context.spec) {
             let topic = GossipTopic::new(kind, GossipEncoding::default(), new_fork_digest);
             self.subscribe(topic);
         }
diff --git a/beacon_node/lighthouse_network/src/types/topics.rs b/beacon_node/lighthouse_network/src/types/topics.rs
index e7e771e1a..b77490517 100644
--- a/beacon_node/lighthouse_network/src/types/topics.rs
+++ b/beacon_node/lighthouse_network/src/types/topics.rs
@@ -1,8 +1,7 @@
 use libp2p::gossipsub::{IdentTopic as Topic, TopicHash};
 use serde::{Deserialize, Serialize};
 use strum::AsRefStr;
-use types::consts::deneb::BLOB_SIDECAR_SUBNET_COUNT;
-use types::{EthSpec, ForkName, SubnetId, SyncSubnetId};
+use types::{ChainSpec, EthSpec, ForkName, SubnetId, SyncSubnetId};
 
 use crate::Subnet;
 
@@ -44,7 +43,7 @@ pub const LIGHT_CLIENT_GOSSIP_TOPICS: [GossipKind; 2] = [
 pub const DENEB_CORE_TOPICS: [GossipKind; 0] = [];
 
 /// Returns the core topics associated with each fork that are new to the previous fork
-pub fn fork_core_topics<T: EthSpec>(fork_name: &ForkName) -> Vec<GossipKind> {
+pub fn fork_core_topics<T: EthSpec>(fork_name: &ForkName, spec: &ChainSpec) -> Vec<GossipKind> {
     match fork_name {
         ForkName::Base => BASE_CORE_TOPICS.to_vec(),
         ForkName::Altair => ALTAIR_CORE_TOPICS.to_vec(),
@@ -53,7 +52,7 @@ pub fn fork_core_topics<T: EthSpec>(fork_name: &ForkName) -> Vec<GossipKind> {
         ForkName::Deneb => {
             // All of deneb blob topics are core topics
             let mut deneb_blob_topics = Vec::new();
-            for i in 0..BLOB_SIDECAR_SUBNET_COUNT {
+            for i in 0..spec.blob_sidecar_subnet_count {
                 deneb_blob_topics.push(GossipKind::BlobSidecar(i));
             }
             let mut deneb_topics = DENEB_CORE_TOPICS.to_vec();
@@ -65,10 +64,13 @@ pub fn fork_core_topics<T: EthSpec>(fork_name: &ForkName) -> Vec<GossipKind> {
 
 /// Returns all the topics that we need to subscribe to for a given fork
 /// including topics from older forks and new topics for the current fork.
-pub fn core_topics_to_subscribe<T: EthSpec>(mut current_fork: ForkName) -> Vec<GossipKind> {
-    let mut topics = fork_core_topics::<T>(&current_fork);
+pub fn core_topics_to_subscribe<T: EthSpec>(
+    mut current_fork: ForkName,
+    spec: &ChainSpec,
+) -> Vec<GossipKind> {
+    let mut topics = fork_core_topics::<T>(&current_fork, spec);
     while let Some(previous_fork) = current_fork.previous_fork() {
-        let previous_fork_topics = fork_core_topics::<T>(&previous_fork);
+        let previous_fork_topics = fork_core_topics::<T>(&previous_fork, spec);
         topics.extend(previous_fork_topics);
         current_fork = previous_fork;
     }
@@ -435,14 +437,18 @@ mod tests {
     #[test]
     fn test_core_topics_to_subscribe() {
         type E = MainnetEthSpec;
+        let spec = E::default_spec();
         let mut all_topics = Vec::new();
-        let mut deneb_core_topics = fork_core_topics::<E>(&ForkName::Deneb);
+        let mut deneb_core_topics = fork_core_topics::<E>(&ForkName::Deneb, &spec);
         all_topics.append(&mut deneb_core_topics);
         all_topics.extend(CAPELLA_CORE_TOPICS);
         all_topics.extend(ALTAIR_CORE_TOPICS);
         all_topics.extend(BASE_CORE_TOPICS);
 
         let latest_fork = *ForkName::list_all().last().unwrap();
-        assert_eq!(core_topics_to_subscribe::<E>(latest_fork), all_topics);
+        assert_eq!(
+            core_topics_to_subscribe::<E>(latest_fork, &spec),
+            all_topics
+        );
     }
 }
diff --git a/beacon_node/lighthouse_network/tests/rpc_tests.rs b/beacon_node/lighthouse_network/tests/rpc_tests.rs
index 176f783c9..643c1231a 100644
--- a/beacon_node/lighthouse_network/tests/rpc_tests.rs
+++ b/beacon_node/lighthouse_network/tests/rpc_tests.rs
@@ -743,15 +743,17 @@ fn test_tcp_blocks_by_root_chunked_rpc() {
         .await;
 
         // BlocksByRoot Request
-        let rpc_request =
-            Request::BlocksByRoot(BlocksByRootRequest::new(VariableList::from(vec![
+        let rpc_request = Request::BlocksByRoot(BlocksByRootRequest::new(
+            vec![
                 Hash256::from_low_u64_be(0),
                 Hash256::from_low_u64_be(0),
                 Hash256::from_low_u64_be(0),
                 Hash256::from_low_u64_be(0),
                 Hash256::from_low_u64_be(0),
                 Hash256::from_low_u64_be(0),
-            ])));
+            ],
+            &spec,
+        ));
 
         // BlocksByRoot Response
         let full_block = BeaconBlock::Base(BeaconBlockBase::<E>::full(&spec));
@@ -876,8 +878,8 @@ fn test_tcp_blocks_by_root_chunked_rpc_terminates_correctly() {
         .await;
 
         // BlocksByRoot Request
-        let rpc_request =
-            Request::BlocksByRoot(BlocksByRootRequest::new(VariableList::from(vec![
+        let rpc_request = Request::BlocksByRoot(BlocksByRootRequest::new(
+            vec![
                 Hash256::from_low_u64_be(0),
                 Hash256::from_low_u64_be(0),
                 Hash256::from_low_u64_be(0),
@@ -888,7 +890,9 @@ fn test_tcp_blocks_by_root_chunked_rpc_terminates_correctly() {
                 Hash256::from_low_u64_be(0),
                 Hash256::from_low_u64_be(0),
                 Hash256::from_low_u64_be(0),
-            ])));
+            ],
+            &spec,
+        ));
 
         // BlocksByRoot Response
         let full_block = BeaconBlock::Base(BeaconBlockBase::<E>::full(&spec));
diff --git a/beacon_node/network/src/network_beacon_processor/rpc_methods.rs b/beacon_node/network/src/network_beacon_processor/rpc_methods.rs
index 430e0571b..a731dea7c 100644
--- a/beacon_node/network/src/network_beacon_processor/rpc_methods.rs
+++ b/beacon_node/network/src/network_beacon_processor/rpc_methods.rs
@@ -5,9 +5,7 @@ use crate::sync::SyncMessage;
 use beacon_chain::{BeaconChainError, BeaconChainTypes, HistoricalBlockError, WhenSlotSkipped};
 use beacon_processor::SendOnDrop;
 use itertools::process_results;
-use lighthouse_network::rpc::methods::{
-    BlobsByRangeRequest, BlobsByRootRequest, MAX_REQUEST_BLOB_SIDECARS, MAX_REQUEST_BLOCKS_DENEB,
-};
+use lighthouse_network::rpc::methods::{BlobsByRangeRequest, BlobsByRootRequest};
 use lighthouse_network::rpc::StatusMessage;
 use lighthouse_network::rpc::*;
 use lighthouse_network::{PeerId, PeerRequestId, ReportSource, Response, SyncInfo};
@@ -222,12 +220,14 @@ impl<T: BeaconChainTypes> NetworkBeaconProcessor<T> {
         request_id: PeerRequestId,
         request: BlobsByRootRequest,
     ) {
-        let Some(requested_root) = request.blob_ids.first().map(|id| id.block_root) else {
+        let Some(requested_root) = request.blob_ids.as_slice().first().map(|id| id.block_root)
+        else {
             // No blob ids requested.
             return;
         };
         let requested_indices = request
             .blob_ids
+            .as_slice()
             .iter()
             .map(|id| id.index)
             .collect::<Vec<_>>();
@@ -235,9 +235,9 @@ impl<T: BeaconChainTypes> NetworkBeaconProcessor<T> {
         let send_response = true;
 
         let mut blob_list_results = HashMap::new();
-        for id in request.blob_ids.into_iter() {
+        for id in request.blob_ids.as_slice() {
             // First attempt to get the blobs from the RPC cache.
-            if let Ok(Some(blob)) = self.chain.data_availability_checker.get_blob(&id) {
+            if let Ok(Some(blob)) = self.chain.data_availability_checker.get_blob(id) {
                 self.send_response(peer_id, Response::BlobsByRoot(Some(blob)), request_id);
                 send_blob_count += 1;
             } else {
@@ -248,7 +248,7 @@ impl<T: BeaconChainTypes> NetworkBeaconProcessor<T> {
 
                 let blob_list_result = match blob_list_results.entry(root) {
                     Entry::Vacant(entry) => {
-                        entry.insert(self.chain.get_blobs_checking_early_attester_cache(&root))
+                        entry.insert(self.chain.get_blobs_checking_early_attester_cache(root))
                     }
                     Entry::Occupied(entry) => entry.into_mut(),
                 };
@@ -256,7 +256,7 @@ impl<T: BeaconChainTypes> NetworkBeaconProcessor<T> {
                 match blob_list_result.as_ref() {
                     Ok(blobs_sidecar_list) => {
                         'inner: for blob_sidecar in blobs_sidecar_list.iter() {
-                            if blob_sidecar.index == index {
+                            if blob_sidecar.index == *index {
                                 self.send_response(
                                     peer_id,
                                     Response::BlobsByRoot(Some(blob_sidecar.clone())),
@@ -346,14 +346,17 @@ impl<T: BeaconChainTypes> NetworkBeaconProcessor<T> {
         );
 
         // Should not send more than max request blocks
-        let max_request_size = self.chain.epoch().map_or(MAX_REQUEST_BLOCKS, |epoch| {
-            match self.chain.spec.fork_name_at_epoch(epoch) {
-                ForkName::Deneb => MAX_REQUEST_BLOCKS_DENEB,
-                ForkName::Base | ForkName::Altair | ForkName::Merge | ForkName::Capella => {
-                    MAX_REQUEST_BLOCKS
-                }
-            }
-        });
+        let max_request_size =
+            self.chain
+                .epoch()
+                .map_or(self.chain.spec.max_request_blocks, |epoch| {
+                    match self.chain.spec.fork_name_at_epoch(epoch) {
+                        ForkName::Deneb => self.chain.spec.max_request_blocks_deneb,
+                        ForkName::Base | ForkName::Altair | ForkName::Merge | ForkName::Capella => {
+                            self.chain.spec.max_request_blocks
+                        }
+                    }
+                });
         if *req.count() > max_request_size {
             return self.send_error_response(
                 peer_id,
@@ -586,7 +589,7 @@ impl<T: BeaconChainTypes> NetworkBeaconProcessor<T> {
         );
 
         // Should not send more than max request blocks
-        if req.max_blobs_requested::<T::EthSpec>() > MAX_REQUEST_BLOB_SIDECARS {
+        if req.max_blobs_requested::<T::EthSpec>() > self.chain.spec.max_request_blob_sidecars {
             return self.send_error_response(
                 peer_id,
                 RPCResponseErrorCode::InvalidRequest,
diff --git a/beacon_node/network/src/service.rs b/beacon_node/network/src/service.rs
index 17760cef5..01a7e1f98 100644
--- a/beacon_node/network/src/service.rs
+++ b/beacon_node/network/src/service.rs
@@ -716,9 +716,10 @@ impl<T: BeaconChainTypes> NetworkService<T> {
                 }
 
                 let mut subscribed_topics: Vec<GossipTopic> = vec![];
-                for topic_kind in
-                    core_topics_to_subscribe::<T::EthSpec>(self.fork_context.current_fork())
-                {
+                for topic_kind in core_topics_to_subscribe::<T::EthSpec>(
+                    self.fork_context.current_fork(),
+                    &self.fork_context.spec,
+                ) {
                     for fork_digest in self.required_gossip_fork_digests() {
                         let topic = GossipTopic::new(
                             topic_kind.clone(),
@@ -945,7 +946,10 @@ impl<T: BeaconChainTypes> NetworkService<T> {
     }
 
     fn subscribed_core_topics(&self) -> bool {
-        let core_topics = core_topics_to_subscribe::<T::EthSpec>(self.fork_context.current_fork());
+        let core_topics = core_topics_to_subscribe::<T::EthSpec>(
+            self.fork_context.current_fork(),
+            &self.fork_context.spec,
+        );
         let core_topics: HashSet<&GossipKind> = HashSet::from_iter(&core_topics);
         let subscriptions = self.network_globals.gossipsub_subscriptions.read();
         let subscribed_topics: HashSet<&GossipKind> =
diff --git a/beacon_node/network/src/sync/block_lookups/common.rs b/beacon_node/network/src/sync/block_lookups/common.rs
index 7a1be46e6..78b10473d 100644
--- a/beacon_node/network/src/sync/block_lookups/common.rs
+++ b/beacon_node/network/src/sync/block_lookups/common.rs
@@ -13,12 +13,11 @@ use beacon_chain::{get_block_root, BeaconChainTypes};
 use lighthouse_network::rpc::methods::BlobsByRootRequest;
 use lighthouse_network::rpc::BlocksByRootRequest;
 use rand::prelude::IteratorRandom;
-use ssz_types::VariableList;
 use std::ops::IndexMut;
 use std::sync::Arc;
 use std::time::Duration;
 use types::blob_sidecar::{BlobIdentifier, FixedBlobSidecarList};
-use types::{BlobSidecar, EthSpec, Hash256, SignedBeaconBlock};
+use types::{BlobSidecar, ChainSpec, EthSpec, Hash256, SignedBeaconBlock};
 
 #[derive(Debug, Copy, Clone)]
 pub enum ResponseType {
@@ -87,11 +86,14 @@ pub trait RequestState<L: Lookup, T: BeaconChainTypes> {
     /* Request building methods */
 
     /// Construct a new request.
-    fn build_request(&mut self) -> Result<(PeerId, Self::RequestType), LookupRequestError> {
+    fn build_request(
+        &mut self,
+        spec: &ChainSpec,
+    ) -> Result<(PeerId, Self::RequestType), LookupRequestError> {
         // Verify and construct request.
         self.too_many_attempts()?;
         let peer = self.get_peer()?;
-        let request = self.new_request();
+        let request = self.new_request(spec);
         Ok((peer, request))
     }
 
@@ -108,7 +110,7 @@ pub trait RequestState<L: Lookup, T: BeaconChainTypes> {
         }
 
         // Construct request.
-        let (peer_id, request) = self.build_request()?;
+        let (peer_id, request) = self.build_request(&cx.chain.spec)?;
 
         // Update request state.
         self.get_state_mut().state = State::Downloading { peer_id };
@@ -151,7 +153,7 @@ pub trait RequestState<L: Lookup, T: BeaconChainTypes> {
     }
 
     /// Initialize `Self::RequestType`.
-    fn new_request(&self) -> Self::RequestType;
+    fn new_request(&self, spec: &ChainSpec) -> Self::RequestType;
 
     /// Send the request to the network service.
     fn make_request(
@@ -254,8 +256,8 @@ impl<L: Lookup, T: BeaconChainTypes> RequestState<L, T> for BlockRequestState<L>
     type VerifiedResponseType = Arc<SignedBeaconBlock<T::EthSpec>>;
     type ReconstructedResponseType = RpcBlock<T::EthSpec>;
 
-    fn new_request(&self) -> BlocksByRootRequest {
-        BlocksByRootRequest::new(VariableList::from(vec![self.requested_block_root]))
+    fn new_request(&self, spec: &ChainSpec) -> BlocksByRootRequest {
+        BlocksByRootRequest::new(vec![self.requested_block_root], spec)
     }
 
     fn make_request(
@@ -353,10 +355,9 @@ impl<L: Lookup, T: BeaconChainTypes> RequestState<L, T> for BlobRequestState<L,
     type VerifiedResponseType = FixedBlobSidecarList<T::EthSpec>;
     type ReconstructedResponseType = FixedBlobSidecarList<T::EthSpec>;
 
-    fn new_request(&self) -> BlobsByRootRequest {
+    fn new_request(&self, spec: &ChainSpec) -> BlobsByRootRequest {
         let blob_id_vec: Vec<BlobIdentifier> = self.requested_ids.clone().into();
-        let blob_ids = VariableList::from(blob_id_vec);
-        BlobsByRootRequest { blob_ids }
+        BlobsByRootRequest::new(blob_id_vec, spec)
     }
 
     fn make_request(
diff --git a/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs b/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs
index e10e8328c..4e2981629 100644
--- a/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs
+++ b/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs
@@ -575,7 +575,7 @@ mod tests {
             HotColdDB::open_ephemeral(StoreConfig::default(), ChainSpec::minimal(), log.clone())
                 .expect("store");
         let da_checker = Arc::new(
-            DataAvailabilityChecker::new(slot_clock, None, store.into(), &log, spec)
+            DataAvailabilityChecker::new(slot_clock, None, store.into(), &log, spec.clone())
                 .expect("data availability checker"),
         );
         let mut sl = SingleBlockLookup::<TestLookup1, T>::new(
@@ -587,6 +587,7 @@ mod tests {
         );
         <BlockRequestState<TestLookup1> as RequestState<TestLookup1, T>>::build_request(
             &mut sl.block_request_state,
+            &spec,
         )
         .unwrap();
         sl.block_request_state.state.state = State::Downloading { peer_id };
@@ -616,7 +617,7 @@ mod tests {
                 .expect("store");
 
         let da_checker = Arc::new(
-            DataAvailabilityChecker::new(slot_clock, None, store.into(), &log, spec)
+            DataAvailabilityChecker::new(slot_clock, None, store.into(), &log, spec.clone())
                 .expect("data availability checker"),
         );
 
@@ -630,6 +631,7 @@ mod tests {
         for _ in 1..TestLookup2::MAX_ATTEMPTS {
             <BlockRequestState<TestLookup2> as RequestState<TestLookup2, T>>::build_request(
                 &mut sl.block_request_state,
+                &spec,
             )
             .unwrap();
             sl.block_request_state.state.register_failure_downloading();
@@ -638,6 +640,7 @@ mod tests {
         // Now we receive the block and send it for processing
         <BlockRequestState<TestLookup2> as RequestState<TestLookup2, T>>::build_request(
             &mut sl.block_request_state,
+            &spec,
         )
         .unwrap();
         sl.block_request_state.state.state = State::Downloading { peer_id };
@@ -654,7 +657,8 @@ mod tests {
         sl.block_request_state.state.register_failure_processing();
         assert_eq!(
             <BlockRequestState<TestLookup2> as RequestState<TestLookup2, T>>::build_request(
-                &mut sl.block_request_state
+                &mut sl.block_request_state,
+                &spec
             ),
             Err(LookupRequestError::TooManyAttempts {
                 cannot_process: false
diff --git a/beacon_node/network/src/sync/manager.rs b/beacon_node/network/src/sync/manager.rs
index bcb239aaa..acb735ea4 100644
--- a/beacon_node/network/src/sync/manager.rs
+++ b/beacon_node/network/src/sync/manager.rs
@@ -52,7 +52,6 @@ use beacon_chain::{
     AvailabilityProcessingStatus, BeaconChain, BeaconChainTypes, BlockError, EngineState,
 };
 use futures::StreamExt;
-use lighthouse_network::rpc::methods::MAX_REQUEST_BLOCKS;
 use lighthouse_network::rpc::RPCError;
 use lighthouse_network::types::{NetworkGlobals, SyncState};
 use lighthouse_network::SyncInfo;
@@ -230,7 +229,7 @@ pub fn spawn<T: BeaconChainTypes>(
     log: slog::Logger,
 ) {
     assert!(
-        MAX_REQUEST_BLOCKS >= T::EthSpec::slots_per_epoch() * EPOCHS_PER_BATCH,
+        beacon_chain.spec.max_request_blocks >= T::EthSpec::slots_per_epoch() * EPOCHS_PER_BATCH,
         "Max blocks that can be requested in a single batch greater than max allowed blocks in a single request"
     );
 
diff --git a/beacon_node/network/src/sync/network_context.rs b/beacon_node/network/src/sync/network_context.rs
index c01bc3e42..04feb8fdc 100644
--- a/beacon_node/network/src/sync/network_context.rs
+++ b/beacon_node/network/src/sync/network_context.rs
@@ -475,9 +475,15 @@ impl<T: BeaconChainTypes> SyncNetworkContext<T> {
         };
         let request_id = RequestId::Sync(sync_id);
 
-        if let Some(block_root) = blob_request.blob_ids.first().map(|id| id.block_root) {
+        if let Some(block_root) = blob_request
+            .blob_ids
+            .as_slice()
+            .first()
+            .map(|id| id.block_root)
+        {
             let indices = blob_request
                 .blob_ids
+                .as_slice()
                 .iter()
                 .map(|id| id.index)
                 .collect::<Vec<_>>();
diff --git a/beacon_node/store/src/hot_cold_store.rs b/beacon_node/store/src/hot_cold_store.rs
index f73c19401..63cd8e67d 100644
--- a/beacon_node/store/src/hot_cold_store.rs
+++ b/beacon_node/store/src/hot_cold_store.rs
@@ -40,7 +40,6 @@ use std::path::Path;
 use std::sync::Arc;
 use std::time::Duration;
 use types::blob_sidecar::BlobSidecarList;
-use types::consts::deneb::MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS;
 use types::*;
 
 /// On-disk database that stores finalized states efficiently.
@@ -2055,7 +2054,7 @@ impl<E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>> HotColdDB<E, Hot, Cold>
         let min_current_epoch = self.get_split_slot().epoch(E::slots_per_epoch()) + 2;
         let min_data_availability_boundary = std::cmp::max(
             deneb_fork_epoch,
-            min_current_epoch.saturating_sub(MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS),
+            min_current_epoch.saturating_sub(self.spec.min_epochs_for_blob_sidecars_requests),
         );
 
         self.try_prune_blobs(force, min_data_availability_boundary)
diff --git a/consensus/state_processing/src/per_block_processing/deneb.rs b/consensus/state_processing/src/per_block_processing/deneb.rs
index 8f7cb0514..217c2ea30 100644
--- a/consensus/state_processing/src/per_block_processing/deneb.rs
+++ b/consensus/state_processing/src/per_block_processing/deneb.rs
@@ -1,6 +1,5 @@
 use ethereum_hashing::hash_fixed;
-use types::consts::deneb::VERSIONED_HASH_VERSION_KZG;
-use types::{KzgCommitment, VersionedHash};
+use types::{KzgCommitment, VersionedHash, VERSIONED_HASH_VERSION_KZG};
 
 pub fn kzg_commitment_to_versioned_hash(kzg_commitment: &KzgCommitment) -> VersionedHash {
     let mut hashed_commitment = hash_fixed(&kzg_commitment.0);
diff --git a/consensus/types/src/chain_spec.rs b/consensus/types/src/chain_spec.rs
index 784d98c13..b2120fb04 100644
--- a/consensus/types/src/chain_spec.rs
+++ b/consensus/types/src/chain_spec.rs
@@ -4,6 +4,7 @@ use int_to_bytes::int_to_bytes4;
 use serde::Deserialize;
 use serde::{Deserializer, Serialize, Serializer};
 use serde_utils::quoted_u64::MaybeQuoted;
+use ssz::Encode;
 use std::fs::File;
 use std::path::Path;
 use std::time::Duration;
@@ -172,22 +173,40 @@ pub struct ChainSpec {
      */
     pub boot_nodes: Vec<String>,
     pub network_id: u8,
-    pub attestation_propagation_slot_range: u64,
-    pub maximum_gossip_clock_disparity_millis: u64,
     pub target_aggregators_per_committee: u64,
-    pub attestation_subnet_count: u64,
-    pub subnets_per_node: u8,
-    pub epochs_per_subnet_subscription: u64,
     pub gossip_max_size: u64,
+    pub max_request_blocks: u64,
+    pub epochs_per_subnet_subscription: u64,
     pub min_epochs_for_block_requests: u64,
     pub max_chunk_size: u64,
     pub ttfb_timeout: u64,
     pub resp_timeout: u64,
+    pub attestation_propagation_slot_range: u64,
+    pub maximum_gossip_clock_disparity_millis: u64,
     pub message_domain_invalid_snappy: [u8; 4],
     pub message_domain_valid_snappy: [u8; 4],
+    pub subnets_per_node: u8,
+    pub attestation_subnet_count: u64,
     pub attestation_subnet_extra_bits: u8,
     pub attestation_subnet_prefix_bits: u8,
 
+    /*
+     * Networking Deneb
+     */
+    pub max_request_blocks_deneb: u64,
+    pub max_request_blob_sidecars: u64,
+    pub min_epochs_for_blob_sidecars_requests: u64,
+    pub blob_sidecar_subnet_count: u64,
+
+    /*
+     * Networking Derived
+     *
+     * When adding fields here, make sure any values are derived again during `apply_to_chain_spec`.
+     */
+    pub max_blocks_by_root_request: usize,
+    pub max_blocks_by_root_request_deneb: usize,
+    pub max_blobs_by_root_request: usize,
+
     /*
      * Application params
      */
@@ -487,6 +506,25 @@ impl ChainSpec {
         Duration::from_secs(self.resp_timeout)
     }
 
+    pub fn max_blocks_by_root_request(&self, fork_name: ForkName) -> usize {
+        match fork_name {
+            ForkName::Base | ForkName::Altair | ForkName::Merge | ForkName::Capella => {
+                self.max_blocks_by_root_request
+            }
+            ForkName::Deneb => self.max_blocks_by_root_request_deneb,
+        }
+    }
+
+    pub fn max_request_blocks(&self, fork_name: ForkName) -> usize {
+        let max_request_blocks = match fork_name {
+            ForkName::Base | ForkName::Altair | ForkName::Merge | ForkName::Capella => {
+                self.max_request_blocks
+            }
+            ForkName::Deneb => self.max_request_blocks_deneb,
+        };
+        max_request_blocks as usize
+    }
+
     /// Returns a `ChainSpec` compatible with the Ethereum Foundation specification.
     pub fn mainnet() -> Self {
         Self {
@@ -648,12 +686,12 @@ impl ChainSpec {
              */
             boot_nodes: vec![],
             network_id: 1, // mainnet network id
-            attestation_propagation_slot_range: 32,
+            attestation_propagation_slot_range: default_attestation_propagation_slot_range(),
             attestation_subnet_count: 64,
             subnets_per_node: 2,
-            maximum_gossip_clock_disparity_millis: 500,
+            maximum_gossip_clock_disparity_millis: default_maximum_gossip_clock_disparity_millis(),
             target_aggregators_per_committee: 16,
-            epochs_per_subnet_subscription: 256,
+            epochs_per_subnet_subscription: default_epochs_per_subnet_subscription(),
             gossip_max_size: default_gossip_max_size(),
             min_epochs_for_block_requests: default_min_epochs_for_block_requests(),
             max_chunk_size: default_max_chunk_size(),
@@ -663,6 +701,23 @@ impl ChainSpec {
             message_domain_valid_snappy: default_message_domain_valid_snappy(),
             attestation_subnet_extra_bits: default_attestation_subnet_extra_bits(),
             attestation_subnet_prefix_bits: default_attestation_subnet_prefix_bits(),
+            max_request_blocks: default_max_request_blocks(),
+
+            /*
+             * Networking Deneb Specific
+             */
+            max_request_blocks_deneb: default_max_request_blocks_deneb(),
+            max_request_blob_sidecars: default_max_request_blob_sidecars(),
+            min_epochs_for_blob_sidecars_requests: default_min_epochs_for_blob_sidecars_requests(),
+            blob_sidecar_subnet_count: default_blob_sidecar_subnet_count(),
+
+            /*
+             * Derived Deneb Specific
+             */
+            max_blocks_by_root_request: default_max_blocks_by_root_request(),
+            max_blocks_by_root_request_deneb: default_max_blocks_by_root_request_deneb(),
+            max_blobs_by_root_request: default_max_blobs_by_root_request(),
+
             /*
              * Application specific
              */
@@ -892,12 +947,12 @@ impl ChainSpec {
              */
             boot_nodes: vec![],
             network_id: 100, // Gnosis Chain network id
-            attestation_propagation_slot_range: 32,
+            attestation_propagation_slot_range: default_attestation_propagation_slot_range(),
             attestation_subnet_count: 64,
             subnets_per_node: 4, // Make this larger than usual to avoid network damage
-            maximum_gossip_clock_disparity_millis: 500,
+            maximum_gossip_clock_disparity_millis: default_maximum_gossip_clock_disparity_millis(),
             target_aggregators_per_committee: 16,
-            epochs_per_subnet_subscription: 256,
+            epochs_per_subnet_subscription: default_epochs_per_subnet_subscription(),
             gossip_max_size: default_gossip_max_size(),
             min_epochs_for_block_requests: default_min_epochs_for_block_requests(),
             max_chunk_size: default_max_chunk_size(),
@@ -907,6 +962,22 @@ impl ChainSpec {
             message_domain_valid_snappy: default_message_domain_valid_snappy(),
             attestation_subnet_extra_bits: default_attestation_subnet_extra_bits(),
             attestation_subnet_prefix_bits: default_attestation_subnet_prefix_bits(),
+            max_request_blocks: default_max_request_blocks(),
+
+            /*
+             * Networking Deneb Specific
+             */
+            max_request_blocks_deneb: default_max_request_blocks_deneb(),
+            max_request_blob_sidecars: default_max_request_blob_sidecars(),
+            min_epochs_for_blob_sidecars_requests: default_min_epochs_for_blob_sidecars_requests(),
+            blob_sidecar_subnet_count: default_blob_sidecar_subnet_count(),
+
+            /*
+             * Derived Deneb Specific
+             */
+            max_blocks_by_root_request: default_max_blocks_by_root_request(),
+            max_blocks_by_root_request_deneb: default_max_blocks_by_root_request_deneb(),
+            max_blobs_by_root_request: default_max_blobs_by_root_request(),
 
             /*
              * Application specific
@@ -1032,6 +1103,12 @@ pub struct Config {
     #[serde(default = "default_gossip_max_size")]
     #[serde(with = "serde_utils::quoted_u64")]
     gossip_max_size: u64,
+    #[serde(default = "default_max_request_blocks")]
+    #[serde(with = "serde_utils::quoted_u64")]
+    max_request_blocks: u64,
+    #[serde(default = "default_epochs_per_subnet_subscription")]
+    #[serde(with = "serde_utils::quoted_u64")]
+    epochs_per_subnet_subscription: u64,
     #[serde(default = "default_min_epochs_for_block_requests")]
     #[serde(with = "serde_utils::quoted_u64")]
     min_epochs_for_block_requests: u64,
@@ -1044,6 +1121,12 @@ pub struct Config {
     #[serde(default = "default_resp_timeout")]
     #[serde(with = "serde_utils::quoted_u64")]
     resp_timeout: u64,
+    #[serde(default = "default_attestation_propagation_slot_range")]
+    #[serde(with = "serde_utils::quoted_u64")]
+    attestation_propagation_slot_range: u64,
+    #[serde(default = "default_maximum_gossip_clock_disparity_millis")]
+    #[serde(with = "serde_utils::quoted_u64")]
+    maximum_gossip_clock_disparity_millis: u64,
     #[serde(default = "default_message_domain_invalid_snappy")]
     #[serde(with = "serde_utils::bytes_4_hex")]
     message_domain_invalid_snappy: [u8; 4],
@@ -1056,6 +1139,18 @@ pub struct Config {
     #[serde(default = "default_attestation_subnet_prefix_bits")]
     #[serde(with = "serde_utils::quoted_u8")]
     attestation_subnet_prefix_bits: u8,
+    #[serde(default = "default_max_request_blocks_deneb")]
+    #[serde(with = "serde_utils::quoted_u64")]
+    max_request_blocks_deneb: u64,
+    #[serde(default = "default_max_request_blob_sidecars")]
+    #[serde(with = "serde_utils::quoted_u64")]
+    max_request_blob_sidecars: u64,
+    #[serde(default = "default_min_epochs_for_blob_sidecars_requests")]
+    #[serde(with = "serde_utils::quoted_u64")]
+    min_epochs_for_blob_sidecars_requests: u64,
+    #[serde(default = "default_blob_sidecar_subnet_count")]
+    #[serde(with = "serde_utils::quoted_u64")]
+    blob_sidecar_subnet_count: u64,
 }
 
 fn default_bellatrix_fork_version() -> [u8; 4] {
@@ -1141,6 +1236,70 @@ const fn default_attestation_subnet_prefix_bits() -> u8 {
     6
 }
 
+const fn default_max_request_blocks() -> u64 {
+    1024
+}
+
+const fn default_max_request_blocks_deneb() -> u64 {
+    128
+}
+
+const fn default_max_request_blob_sidecars() -> u64 {
+    768
+}
+
+const fn default_min_epochs_for_blob_sidecars_requests() -> u64 {
+    4096
+}
+
+const fn default_blob_sidecar_subnet_count() -> u64 {
+    6
+}
+
+const fn default_epochs_per_subnet_subscription() -> u64 {
+    256
+}
+
+const fn default_attestation_propagation_slot_range() -> u64 {
+    32
+}
+
+const fn default_maximum_gossip_clock_disparity_millis() -> u64 {
+    500
+}
+
+fn max_blocks_by_root_request_common(max_request_blocks: u64) -> usize {
+    let max_request_blocks = max_request_blocks as usize;
+    RuntimeVariableList::<Hash256>::from_vec(
+        vec![Hash256::zero(); max_request_blocks],
+        max_request_blocks,
+    )
+    .as_ssz_bytes()
+    .len()
+}
+
+fn max_blobs_by_root_request_common(max_request_blob_sidecars: u64) -> usize {
+    let max_request_blob_sidecars = max_request_blob_sidecars as usize;
+    RuntimeVariableList::<Hash256>::from_vec(
+        vec![Hash256::zero(); max_request_blob_sidecars],
+        max_request_blob_sidecars,
+    )
+    .as_ssz_bytes()
+    .len()
+}
+
+fn default_max_blocks_by_root_request() -> usize {
+    max_blocks_by_root_request_common(default_max_request_blocks())
+}
+
+fn default_max_blocks_by_root_request_deneb() -> usize {
+    max_blocks_by_root_request_common(default_max_request_blocks_deneb())
+}
+
+fn default_max_blobs_by_root_request() -> usize {
+    max_blobs_by_root_request_common(default_max_request_blob_sidecars())
+}
+
 impl Default for Config {
     fn default() -> Self {
         let chain_spec = MainnetEthSpec::default_spec();
@@ -1243,14 +1402,22 @@ impl Config {
             deposit_contract_address: spec.deposit_contract_address,
 
             gossip_max_size: spec.gossip_max_size,
+            max_request_blocks: spec.max_request_blocks,
+            epochs_per_subnet_subscription: spec.epochs_per_subnet_subscription,
             min_epochs_for_block_requests: spec.min_epochs_for_block_requests,
             max_chunk_size: spec.max_chunk_size,
             ttfb_timeout: spec.ttfb_timeout,
             resp_timeout: spec.resp_timeout,
+            attestation_propagation_slot_range: spec.attestation_propagation_slot_range,
+            maximum_gossip_clock_disparity_millis: spec.maximum_gossip_clock_disparity_millis,
             message_domain_invalid_snappy: spec.message_domain_invalid_snappy,
             message_domain_valid_snappy: spec.message_domain_valid_snappy,
             attestation_subnet_extra_bits: spec.attestation_subnet_extra_bits,
             attestation_subnet_prefix_bits: spec.attestation_subnet_prefix_bits,
+            max_request_blocks_deneb: spec.max_request_blocks_deneb,
+            max_request_blob_sidecars: spec.max_request_blob_sidecars,
+            min_epochs_for_blob_sidecars_requests: spec.min_epochs_for_blob_sidecars_requests,
+            blob_sidecar_subnet_count: spec.blob_sidecar_subnet_count,
         }
     }
 
@@ -1307,6 +1474,14 @@ impl Config {
             message_domain_valid_snappy,
             attestation_subnet_extra_bits,
             attestation_subnet_prefix_bits,
+            max_request_blocks,
+            epochs_per_subnet_subscription,
+            attestation_propagation_slot_range,
+            maximum_gossip_clock_disparity_millis,
+            max_request_blocks_deneb,
+            max_request_blob_sidecars,
+            min_epochs_for_blob_sidecars_requests,
+            blob_sidecar_subnet_count,
         } = self;
 
         if preset_base != T::spec_name().to_string().as_str() {
@@ -1356,6 +1531,22 @@ impl Config {
             message_domain_valid_snappy,
             attestation_subnet_extra_bits,
             attestation_subnet_prefix_bits,
+            max_request_blocks,
+            epochs_per_subnet_subscription,
+            attestation_propagation_slot_range,
+            maximum_gossip_clock_disparity_millis,
+            max_request_blocks_deneb,
+            max_request_blob_sidecars,
+            min_epochs_for_blob_sidecars_requests,
+            blob_sidecar_subnet_count,
+
+            // We need to re-derive any values that might have changed in the config.
+            max_blocks_by_root_request: max_blocks_by_root_request_common(max_request_blocks),
+            max_blocks_by_root_request_deneb: max_blocks_by_root_request_common(
+                max_request_blocks_deneb,
+            ),
+            max_blobs_by_root_request: max_blobs_by_root_request_common(max_request_blob_sidecars),
+
             ..chain_spec.clone()
         })
     }
diff --git a/consensus/types/src/consts.rs b/consensus/types/src/consts.rs
index f93c75ee8..a9377bc3e 100644
--- a/consensus/types/src/consts.rs
+++ b/consensus/types/src/consts.rs
@@ -22,11 +22,3 @@ pub mod altair {
 pub mod merge {
     pub const INTERVALS_PER_SLOT: u64 = 3;
 }
-pub mod deneb {
-    use crate::Epoch;
-
-    pub const VERSIONED_HASH_VERSION_KZG: u8 = 1;
-    pub const BLOB_SIDECAR_SUBNET_COUNT: u64 = 6;
-    pub const MAX_BLOBS_PER_BLOCK: u64 = BLOB_SIDECAR_SUBNET_COUNT;
-    pub const MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS: Epoch = Epoch::new(4096);
-}
diff --git a/consensus/types/src/fork_context.rs b/consensus/types/src/fork_context.rs
index 23163f0ee..999289271 100644
--- a/consensus/types/src/fork_context.rs
+++ b/consensus/types/src/fork_context.rs
@@ -9,6 +9,7 @@ pub struct ForkContext {
     current_fork: RwLock<ForkName>,
     fork_to_digest: HashMap<ForkName, [u8; 4]>,
     digest_to_fork: HashMap<[u8; 4], ForkName>,
+    pub spec: ChainSpec,
 }
 
 impl ForkContext {
@@ -73,6 +74,7 @@ impl ForkContext {
             current_fork: RwLock::new(spec.fork_name_at_slot::<T>(current_slot)),
             fork_to_digest,
             digest_to_fork,
+            spec: spec.clone(),
         }
     }
 
diff --git a/consensus/types/src/lib.rs b/consensus/types/src/lib.rs
index 52be2fff4..b07b497a2 100644
--- a/consensus/types/src/lib.rs
+++ b/consensus/types/src/lib.rs
@@ -101,6 +101,7 @@ pub mod sqlite;
 pub mod blob_sidecar;
 pub mod light_client_header;
 pub mod non_zero_usize;
+pub mod runtime_var_list;
 
 use ethereum_types::{H160, H256};
 
@@ -168,6 +169,7 @@ pub use crate::preset::{AltairPreset, BasePreset, BellatrixPreset, CapellaPreset
 pub use crate::proposer_preparation_data::ProposerPreparationData;
 pub use crate::proposer_slashing::ProposerSlashing;
 pub use crate::relative_epoch::{Error as RelativeEpochError, RelativeEpoch};
+pub use crate::runtime_var_list::RuntimeVariableList;
 pub use crate::selection_proof::SelectionProof;
 pub use crate::shuffling_id::AttestationShufflingId;
 pub use crate::signed_aggregate_and_proof::SignedAggregateAndProof;
@@ -216,7 +218,7 @@ pub use bls::{
     Signature, SignatureBytes,
 };
 
-pub use kzg::{KzgCommitment, KzgProof};
+pub use kzg::{KzgCommitment, KzgProof, VERSIONED_HASH_VERSION_KZG};
 
 pub use ssz_types::{typenum, typenum::Unsigned, BitList, BitVector, FixedVector, VariableList};
 pub use superstruct::superstruct;
diff --git a/consensus/types/src/runtime_var_list.rs b/consensus/types/src/runtime_var_list.rs
new file mode 100644
index 000000000..84ad5d074
--- /dev/null
+++ b/consensus/types/src/runtime_var_list.rs
@@ -0,0 +1,137 @@
+use ssz::{Decode, Encode};
+use ssz_derive::Encode;
+
+#[derive(Debug, Clone, PartialEq, Encode)]
+#[ssz(struct_behaviour = "transparent")]
+pub struct RuntimeVariableList<T: Encode> {
+    vec: Vec<T>,
+    #[ssz(skip_serializing, skip_deserializing)]
+    max_len: usize,
+}
+
+impl<T: Encode + Decode + Clone> RuntimeVariableList<T> {
+    pub fn new(vec: Vec<T>, max_len: usize) -> Result<Self, ssz_types::Error> {
+        if vec.len() <= max_len {
+            Ok(Self { vec, max_len })
+        } else {
+            Err(ssz_types::Error::OutOfBounds {
+                i: vec.len(),
+                len: max_len,
+            })
+        }
+    }
+
+    pub fn from_vec(mut vec: Vec<T>, max_len: usize) -> Self {
+        vec.truncate(max_len);
+
+        Self { vec, max_len }
+    }
+
+    pub fn to_vec(&self) -> Vec<T> {
+        self.vec.clone()
+    }
+
+    pub fn as_slice(&self) -> &[T] {
+        self.vec.as_slice()
+    }
+
+    pub fn len(&self) -> usize {
+        self.vec.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.vec.is_empty()
+    }
+
+    pub fn from_ssz_bytes(bytes: &[u8], max_len: usize) -> Result<Self, ssz::DecodeError> {
+        let vec = if bytes.is_empty() {
+            vec![]
+        } else if <T as Decode>::is_ssz_fixed_len() {
+            let num_items = bytes
+                .len()
+                .checked_div(<T as Decode>::ssz_fixed_len())
+                .ok_or(ssz::DecodeError::ZeroLengthItem)?;
+
+            if num_items > max_len {
+                return Err(ssz::DecodeError::BytesInvalid(format!(
+                    "VariableList of {} items exceeds maximum of {}",
+                    num_items, max_len
+                )));
+            }
+
+            bytes
+                .chunks(<T as Decode>::ssz_fixed_len())
+                .try_fold(Vec::with_capacity(num_items), |mut vec, chunk| {
+                    vec.push(<T as Decode>::from_ssz_bytes(chunk)?);
+                    Ok(vec)
+                })
+                .map(Into::into)?
+        } else {
+            ssz::decode_list_of_variable_length_items(bytes, Some(max_len))?
+        };
+        Ok(Self { vec, max_len })
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use ssz_types::{typenum::U4, VariableList};
+
+    use super::*;
+
+    #[test]
+    fn new() {
+        let vec = vec![42; 5];
+        let runtime_var_list: Result<RuntimeVariableList<u64>, _> =
+            RuntimeVariableList::new(vec, 4);
+        assert!(runtime_var_list.is_err());
+
+        let vec = vec![42; 3];
+        let runtime_var_list: Result<RuntimeVariableList<u64>, _> =
+            RuntimeVariableList::new(vec, 4);
+        assert!(runtime_var_list.is_ok());
+
+        let vec = vec![42; 4];
+        let runtime_var_list: Result<RuntimeVariableList<u64>, _> =
+            RuntimeVariableList::new(vec, 4);
+        assert!(runtime_var_list.is_ok());
+    }
+
+    #[test]
+    fn length() {
+        let vec = vec![42; 3];
+        let runtime_var_list: RuntimeVariableList<u64> =
+            RuntimeVariableList::new(vec.clone(), 4).unwrap();
+        let var_list: VariableList<u64, U4> = VariableList::from(vec.clone());
+        assert_eq!(&runtime_var_list.as_slice()[0..3], &vec[..]);
+        assert_eq!(runtime_var_list.as_slice(), &vec![42, 42, 42][..]);
+        assert_eq!(runtime_var_list.len(), var_list.len());
+
+        let vec = vec![];
+        let runtime_var_list: RuntimeVariableList<u64> = RuntimeVariableList::new(vec, 4).unwrap();
+        assert_eq!(runtime_var_list.as_slice(), &[] as &[u64]);
+        assert!(runtime_var_list.is_empty());
+    }
+
+    #[test]
+    fn encode() {
+        let runtime_var_list: RuntimeVariableList<u16> =
+            RuntimeVariableList::new(vec![0; 2], 2).unwrap();
+
+        assert_eq!(runtime_var_list.as_ssz_bytes(), vec![0, 0, 0, 0]);
+        assert_eq!(<RuntimeVariableList<u16> as Encode>::ssz_fixed_len(), 4);
+    }
+
+    #[test]
+    fn round_trip() {
+        let item = RuntimeVariableList::<u16>::new(vec![42; 8], 8).unwrap();
+        let encoded = &item.as_ssz_bytes();
+        assert_eq!(item.ssz_bytes_len(), encoded.len());
+        assert_eq!(RuntimeVariableList::from_ssz_bytes(encoded, 8), Ok(item));
+
+        let item = RuntimeVariableList::<u16>::new(vec![0; 8], 8).unwrap();
+        let encoded = &item.as_ssz_bytes();
+        assert_eq!(item.ssz_bytes_len(), encoded.len());
+        assert_eq!(RuntimeVariableList::from_ssz_bytes(encoded, 8), Ok(item));
+    }
+}
diff --git a/crypto/kzg/src/lib.rs b/crypto/kzg/src/lib.rs
index cb5212aea..0e096ba55 100644
--- a/crypto/kzg/src/lib.rs
+++ b/crypto/kzg/src/lib.rs
@@ -4,12 +4,15 @@ mod trusted_setup;
 
 use std::fmt::Debug;
 
-pub use crate::{kzg_commitment::KzgCommitment, kzg_proof::KzgProof, trusted_setup::TrustedSetup};
+pub use crate::{
+    kzg_commitment::{KzgCommitment, VERSIONED_HASH_VERSION_KZG},
+    kzg_proof::KzgProof,
+    trusted_setup::TrustedSetup,
+};
 pub use c_kzg::{
     Blob, Bytes32, Bytes48, KzgSettings, BYTES_PER_BLOB, BYTES_PER_COMMITMENT,
     BYTES_PER_FIELD_ELEMENT, BYTES_PER_PROOF, FIELD_ELEMENTS_PER_BLOB,
 };
-
 #[derive(Debug)]
 pub enum Error {
     /// An error from the underlying kzg library.