diff --git a/packages/beacon-node/src/chain/chain.ts b/packages/beacon-node/src/chain/chain.ts
index 792f5d61d168..3fd06d34f794 100644
--- a/packages/beacon-node/src/chain/chain.ts
+++ b/packages/beacon-node/src/chain/chain.ts
@@ -29,7 +29,7 @@ import {
 import {CheckpointWithHex, ExecutionStatus, IForkChoice, ProtoBlock} from "@lodestar/fork-choice";
 import {ProcessShutdownCallback} from "@lodestar/validator";
 import {Logger, isErrorAborted, pruneSetToMax, sleep, toHex} from "@lodestar/utils";
-import {ForkSeq, SLOTS_PER_EPOCH} from "@lodestar/params";
+import {ForkSeq, SLOTS_PER_EPOCH, GENESIS_SLOT} from "@lodestar/params";
 
 import {toHexString} from "@lodestar/utils";
 import {GENESIS_EPOCH, ZERO_HASH} from "../constants/index.js";
@@ -43,7 +43,6 @@ import {isOptimisticBlock} from "../util/forkChoice.js";
 import {
   blindedOrFullBlockToFull,
   deserializeFullOrBlindedSignedBeaconBlock,
-  getEth1BlockHashFromSerializedBlock,
   serializeFullOrBlindedSignedBeaconBlock,
 } from "../util/fullOrBlindedBlock.js";
 import {ExecutionPayloadBody} from "../execution/engine/types.js";
@@ -470,6 +469,7 @@ export class BeaconChain implements IBeaconChain {
   }
 
   async blindedOrFullBlockToFull(block: allForks.FullOrBlindedSignedBeaconBlock): Promise<allForks.SignedBeaconBlock> {
+    if (block.message.slot === GENESIS_SLOT) return block;
     const info = this.config.getForkInfo(block.message.slot);
     return blindedOrFullBlockToFull(
       this.config,
@@ -479,15 +479,10 @@ export class BeaconChain implements IBeaconChain {
     );
   }
 
-  async blindedOrFullBlockToFullBytes(forkSeq: ForkSeq, block: Uint8Array): Promise<Uint8Array> {
+  async blindedOrFullBlockToFullBytes(block: Uint8Array): Promise<Uint8Array> {
     return serializeFullOrBlindedSignedBeaconBlock(
       this.config,
-      blindedOrFullBlockToFull(
-        this.config,
-        forkSeq,
-        deserializeFullOrBlindedSignedBeaconBlock(this.config, block),
-        await this.getTransactionsAndWithdrawals(forkSeq, toHexString(getEth1BlockHashFromSerializedBlock(block)))
-      )
+      await this.blindedOrFullBlockToFull(deserializeFullOrBlindedSignedBeaconBlock(this.config, block))
     );
   }
 
diff --git a/packages/beacon-node/src/chain/interface.ts b/packages/beacon-node/src/chain/interface.ts
index 59f3e1d4f7d5..417e8e69108d 100644
--- a/packages/beacon-node/src/chain/interface.ts
+++ b/packages/beacon-node/src/chain/interface.ts
@@ -10,7 +10,6 @@ import {BeaconConfig} from "@lodestar/config";
 import {Logger} from "@lodestar/utils";
 
 import {IForkChoice, ProtoBlock} from "@lodestar/fork-choice";
-import {ForkSeq} from "@lodestar/params";
 import {IEth1ForBlockProduction} from "../eth1/index.js";
 import {IExecutionEngine, IExecutionBuilder} from "../execution/index.js";
 import {Metrics} from "../metrics/metrics.js";
@@ -145,7 +144,7 @@ export interface IBeaconChain {
   ): Promise<{block: allForks.BlindedBeaconBlock; executionPayloadValue: Wei}>;
 
   blindedOrFullBlockToFull(block: allForks.FullOrBlindedSignedBeaconBlock): Promise<allForks.SignedBeaconBlock>;
-  blindedOrFullBlockToFullBytes(forkSeq: ForkSeq, block: Uint8Array): Promise<Uint8Array>;
+  blindedOrFullBlockToFullBytes(block: Uint8Array): Promise<Uint8Array>;
 
   /** Process a block until complete */
   processBlock(block: BlockInput, opts?: ImportBlockOpts): Promise<void>;
diff --git a/packages/beacon-node/src/network/reqresp/handlers/beaconBlocksByRange.ts b/packages/beacon-node/src/network/reqresp/handlers/beaconBlocksByRange.ts
index c6ce01f47f58..56533596c2f2 100644
--- a/packages/beacon-node/src/network/reqresp/handlers/beaconBlocksByRange.ts
+++ b/packages/beacon-node/src/network/reqresp/handlers/beaconBlocksByRange.ts
@@ -23,10 +23,9 @@ export async function* onBeaconBlocksByRange(
   if (startSlot <= finalizedSlot) {
     // Chain of blobs won't change
     for await (const {key, value} of finalized.binaryEntriesStream({gte: startSlot, lt: endSlot})) {
-      const {name, seq} = chain.config.getForkInfo(finalized.decodeKey(key));
       yield {
-        data: await chain.blindedOrFullBlockToFullBytes(seq, value),
-        fork: name,
+        data: await chain.blindedOrFullBlockToFullBytes(value),
+        fork: chain.config.getForkName(finalized.decodeKey(key)),
       };
     }
   }
@@ -55,10 +54,9 @@ export async function* onBeaconBlocksByRange(
           throw new ResponseError(RespStatus.SERVER_ERROR, `No item for root ${block.blockRoot} slot ${block.slot}`);
         }
 
-        const {name, seq} = chain.config.getForkInfo(block.slot);
         yield {
-          data: await chain.blindedOrFullBlockToFullBytes(seq, blockBytes),
-          fork: name,
+          data: await chain.blindedOrFullBlockToFullBytes(blockBytes),
+          fork: chain.config.getForkName(block.slot),
         };
       }
 
diff --git a/packages/beacon-node/src/network/reqresp/handlers/beaconBlocksByRoot.ts b/packages/beacon-node/src/network/reqresp/handlers/beaconBlocksByRoot.ts
index bf3b928a5a3f..ba709633c173 100644
--- a/packages/beacon-node/src/network/reqresp/handlers/beaconBlocksByRoot.ts
+++ b/packages/beacon-node/src/network/reqresp/handlers/beaconBlocksByRoot.ts
@@ -38,11 +38,9 @@ export async function* onBeaconBlocksByRoot(
         slot = slotFromBytes;
       }
 
-      const {name, seq} = chain.config.getForkInfo(slot);
-
       yield {
-        data: await chain.blindedOrFullBlockToFullBytes(seq, blockBytes),
-        fork: name,
+        data: await chain.blindedOrFullBlockToFullBytes(blockBytes),
+        fork: chain.config.getForkName(slot),
       };
     }
   }
diff --git a/packages/beacon-node/src/util/fullOrBlindedBlock.ts b/packages/beacon-node/src/util/fullOrBlindedBlock.ts
index 7cf46c084013..a04c2ae04065 100644
--- a/packages/beacon-node/src/util/fullOrBlindedBlock.ts
+++ b/packages/beacon-node/src/util/fullOrBlindedBlock.ts
@@ -3,7 +3,7 @@ import {allForks, bellatrix, capella, deneb} from "@lodestar/types";
 import {BYTES_PER_LOGS_BLOOM, ForkSeq, SYNC_COMMITTEE_SIZE} from "@lodestar/params";
 import {executionPayloadToPayloadHeader} from "@lodestar/state-transition";
 import {ExecutionPayloadBody} from "../execution/engine/types.js";
-import {ROOT_SIZE, getSlotFromSignedBeaconBlockSerialized} from "./sszBytes.js";
+import {getSlotFromSignedBeaconBlockSerialized} from "./sszBytes.js";
 
 /**
  *  * class SignedBeaconBlock(Container):
@@ -49,15 +49,7 @@ const BEACON_BLOCK_FIXED_LENGTH = 8 + 8 + 32 + 32 + 4;
  * Deneb:
  *   blobKzgCommitments             [offset -  4 bytes]
  */
-
-const LOCATION_OF_ETH1_BLOCK_HASH = 96 + 32 + 8;
-export function getEth1BlockHashFromSerializedBlock(block: Uint8Array): Uint8Array {
-  const firstByte = SIGNED_BEACON_BLOCK_FIXED_LENGTH + BEACON_BLOCK_FIXED_LENGTH + LOCATION_OF_ETH1_BLOCK_HASH;
-  return block.slice(firstByte, firstByte + ROOT_SIZE);
-}
-
-const LOCATION_OF_EXECUTION_PAYLOAD_OFFSET =
-  LOCATION_OF_ETH1_BLOCK_HASH + 32 + 32 + 4 + 4 + 4 + 4 + 4 + SYNC_COMMITTEE_SIZE / 8 + 96;
+const LOCATION_OF_EXECUTION_PAYLOAD_OFFSET = 96 + 32 + 8 + 32 + 32 + 4 + 4 + 4 + 4 + 4 + SYNC_COMMITTEE_SIZE / 8 + 96;
 
 /**
  * class ExecutionPayload(Container) or class ExecutionPayloadHeader(Container)