diff --git a/src/Nethermind/Nethermind.Consensus.AuRa/Validators/PendingValidatorsDecoder.cs b/src/Nethermind/Nethermind.Consensus.AuRa/Validators/PendingValidatorsDecoder.cs
index 22e1a168e92..7dc6dcc2894 100644
--- a/src/Nethermind/Nethermind.Consensus.AuRa/Validators/PendingValidatorsDecoder.cs
+++ b/src/Nethermind/Nethermind.Consensus.AuRa/Validators/PendingValidatorsDecoder.cs
@@ -2,7 +2,6 @@
 // SPDX-License-Identifier: LGPL-3.0-only
 
 using System.Collections.Generic;
-using System.Linq;
 using Nethermind.Core;
 using Nethermind.Serialization.Rlp;
 
@@ -84,6 +83,11 @@ private static (int Total, int Addresses) GetContentLength(PendingValidators ite
             return (contentLength, addressesLength);
         }
 
-        private static int GetAddressesLength(Address[] addresses) => addresses.Sum(Rlp.LengthOf);
+        private static int GetAddressesLength(Address[] addresses)
+        {
+            const int AddressLengthWithRlpLengthPrefix = 1 + 20;
+
+            return addresses.Length * AddressLengthWithRlpLengthPrefix;
+        }
     }
 }
diff --git a/src/Nethermind/Nethermind.Core/Eip2930/AccessList.cs b/src/Nethermind/Nethermind.Core/Eip2930/AccessList.cs
index 7d271adc44f..8d5cb5e9e16 100644
--- a/src/Nethermind/Nethermind.Core/Eip2930/AccessList.cs
+++ b/src/Nethermind/Nethermind.Core/Eip2930/AccessList.cs
@@ -116,6 +116,8 @@ public readonly void Dispose() { }
         private readonly int _index;
         private readonly int _count;
 
+        public int Count => _count;
+
         public StorageKeysEnumerable(AccessList accessList, int index, int count)
         {
             _accessList = accessList;
diff --git a/src/Nethermind/Nethermind.Flashbots/Handlers/ValidateBuilderSubmissionHandler.cs b/src/Nethermind/Nethermind.Flashbots/Handlers/ValidateBuilderSubmissionHandler.cs
index 484369ac425..d037584a42f 100644
--- a/src/Nethermind/Nethermind.Flashbots/Handlers/ValidateBuilderSubmissionHandler.cs
+++ b/src/Nethermind/Nethermind.Flashbots/Handlers/ValidateBuilderSubmissionHandler.cs
@@ -3,25 +3,23 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
 using Nethermind.Blockchain;
 using Nethermind.Blockchain.Tracing;
-using Nethermind.Flashbots.Data;
 using Nethermind.Consensus;
 using Nethermind.Consensus.Processing;
 using Nethermind.Consensus.Validators;
 using Nethermind.Core;
+using Nethermind.Core.Crypto;
 using Nethermind.Core.Specs;
 using Nethermind.Crypto;
 using Nethermind.Evm;
-using Nethermind.Evm.Tracing;
+using Nethermind.Evm.State;
+using Nethermind.Flashbots.Data;
 using Nethermind.Int256;
 using Nethermind.JsonRpc;
 using Nethermind.Logging;
 using Nethermind.Merge.Plugin.Data;
-using Nethermind.Core.Crypto;
-using Nethermind.Evm.State;
 using Nethermind.State.OverridableEnv;
 
 namespace Nethermind.Flashbots.Handlers;
@@ -147,7 +145,15 @@ private bool ValidateBlock(Block block, BidTrace message, long registeredGasLimi
     private bool ValidateBlobsBundle(Transaction[] transactions, BlobsBundleV1 blobsBundle, out string? error)
     {
         // get sum of length of blobs of each transaction
-        int totalBlobsLength = transactions.Sum(t => t.BlobVersionedHashes is not null ? t.BlobVersionedHashes.Length : 0);
+        int totalBlobsLength = 0;
+        foreach (Transaction tx in transactions)
+        {
+            byte[]?[]? versionedHashes = tx.BlobVersionedHashes;
+            if (versionedHashes is not null)
+            {
+                totalBlobsLength += versionedHashes.Length;
+            }
+        }
 
         if (totalBlobsLength != blobsBundle.Blobs.Length)
         {
diff --git a/src/Nethermind/Nethermind.Serialization.Rlp/BlockBodyDecoder.cs b/src/Nethermind/Nethermind.Serialization.Rlp/BlockBodyDecoder.cs
index d3b619a846b..f7fc6028159 100644
--- a/src/Nethermind/Nethermind.Serialization.Rlp/BlockBodyDecoder.cs
+++ b/src/Nethermind/Nethermind.Serialization.Rlp/BlockBodyDecoder.cs
@@ -2,7 +2,6 @@
 // SPDX-License-Identifier: LGPL-3.0-only
 
 using System;
-using System.Linq;
 using Nethermind.Core;
 
 namespace Nethermind.Serialization.Rlp;
@@ -41,11 +40,44 @@ public int GetBodyLength(BlockBody b)
         b.Withdrawals is not null ? GetWithdrawalsLength(b.Withdrawals) : null
     );
 
-    private int GetTxLength(Transaction[] transactions) => transactions.Sum(t => _txDecoder.GetLength(t, RlpBehaviors.None));
+    private int GetTxLength(Transaction[] transactions)
+    {
+        if (transactions.Length == 0) return 0;
+
+        int sum = 0;
+        foreach (Transaction tx in transactions)
+        {
+            sum += _txDecoder.GetLength(tx, RlpBehaviors.None);
+        }
+
+        return sum;
+    }
+
+    private int GetUnclesLength(BlockHeader[] headers)
+    {
+        if (headers.Length == 0) return 0;
+
+        int sum = 0;
+        foreach (BlockHeader header in headers)
+        {
+            sum += _headerDecoder.GetLength(header, RlpBehaviors.None);
+        }
 
-    private int GetUnclesLength(BlockHeader[] headers) => headers.Sum(t => _headerDecoder.GetLength(t, RlpBehaviors.None));
+        return sum;
+    }
+
+    private int GetWithdrawalsLength(Withdrawal[] withdrawals)
+    {
+        if (withdrawals.Length == 0) return 0;
 
-    private int GetWithdrawalsLength(Withdrawal[] withdrawals) => withdrawals.Sum(t => _withdrawalDecoderDecoder.GetLength(t, RlpBehaviors.None));
+        int sum = 0;
+        foreach (Withdrawal withdrawal in withdrawals)
+        {
+            sum += _withdrawalDecoderDecoder.GetLength(withdrawal, RlpBehaviors.None);
+        }
+
+        return sum;
+    }
 
     public BlockBody? Decode(ref Rlp.ValueDecoderContext ctx, RlpBehaviors rlpBehaviors = RlpBehaviors.None)
     {
diff --git a/src/Nethermind/Nethermind.Serialization.Rlp/Eip2930/AccessListDecoder.cs b/src/Nethermind/Nethermind.Serialization.Rlp/Eip2930/AccessListDecoder.cs
index 47cd8b2a634..e61b35690cc 100644
--- a/src/Nethermind/Nethermind.Serialization.Rlp/Eip2930/AccessListDecoder.cs
+++ b/src/Nethermind/Nethermind.Serialization.Rlp/Eip2930/AccessListDecoder.cs
@@ -1,7 +1,6 @@
 // SPDX-FileCopyrightText: 2022 Demerzel Solutions Limited
 // SPDX-License-Identifier: LGPL-3.0-only
 
-using System.Linq;
 using Nethermind.Core;
 using Nethermind.Core.Eip2930;
 using Nethermind.Int256;
@@ -151,7 +150,7 @@ public void Encode(RlpStream stream, AccessList? item, RlpBehaviors rlpBehaviors
                 //   Index2
                 //   ...
                 //   IndexN
-                AccessItemLengths lengths = new(storageKeys.Count());
+                AccessItemLengths lengths = new(storageKeys.Count);
                 stream.StartSequence(lengths.ContentLength);
                 {
                     stream.Encode(address);
@@ -199,9 +198,15 @@ public AccessItemLengths(int indexesCount)
 
         private static int GetContentLength(AccessList accessList)
         {
-            return accessList
-                .Select(static entry => new AccessItemLengths(entry.StorageKeys.Count()))
-                .Sum(static lengths => lengths.SequenceLength);
+            int sum = 0;
+            foreach ((Address Address, AccessList.StorageKeysEnumerable StorageKeys) entry in accessList)
+            {
+                int indexesContentLength = entry.StorageKeys.Count * Rlp.LengthOfKeccakRlp;
+                int contentLength = Rlp.LengthOfSequence(indexesContentLength) + Rlp.LengthOfAddressRlp;
+                sum += Rlp.LengthOfSequence(contentLength);
+            }
+
+            return sum;
         }
     }
 }