diff --git a/crates/consensus/src/header.rs b/crates/consensus/src/header.rs
index 8ab3a9f99c7..73dc7ec0db3 100644
--- a/crates/consensus/src/header.rs
+++ b/crates/consensus/src/header.rs
@@ -60,10 +60,10 @@ pub struct Header {
     pub number: BlockNumber,
     /// A scalar value equal to the current limit of gas expenditure per block; formally Hl.
     #[cfg_attr(feature = "serde", serde(with = "alloy_serde::quantity"))]
-    pub gas_limit: u128,
+    pub gas_limit: u64,
     /// A scalar value equal to the total gas used in transactions in this block; formally Hg.
     #[cfg_attr(feature = "serde", serde(with = "alloy_serde::quantity"))]
-    pub gas_used: u128,
+    pub gas_used: u64,
     /// A scalar value equal to the reasonable output of Unix’s time() at this block’s inception;
     /// formally Hs.
     #[cfg_attr(feature = "serde", serde(with = "alloy_serde::quantity"))]
@@ -231,11 +231,11 @@ impl Header {
     /// Calculate base fee for next block according to the EIP-1559 spec.
     ///
     /// Returns a `None` if no base fee is set, no EIP-1559 support
-    pub fn next_block_base_fee(&self, base_fee_params: BaseFeeParams) -> Option<u128> {
+    pub fn next_block_base_fee(&self, base_fee_params: BaseFeeParams) -> Option<u64> {
         Some(calc_next_block_base_fee(
             self.gas_used,
             self.gas_limit,
-            self.base_fee_per_gas?,
+            self.base_fee_per_gas? as u64,
             base_fee_params,
         ))
     }
@@ -493,8 +493,8 @@ impl Decodable for Header {
             logs_bloom: Decodable::decode(buf)?,
             difficulty: Decodable::decode(buf)?,
             number: u64::decode(buf)?,
-            gas_limit: u128::decode(buf)?,
-            gas_used: u128::decode(buf)?,
+            gas_limit: u64::decode(buf)?,
+            gas_used: u64::decode(buf)?,
             timestamp: Decodable::decode(buf)?,
             extra_data: Decodable::decode(buf)?,
             mix_hash: Decodable::decode(buf)?,
@@ -680,10 +680,10 @@ pub trait BlockHeader {
     fn number(&self) -> BlockNumber;
 
     /// Retrieves the gas limit of the block
-    fn gas_limit(&self) -> u128;
+    fn gas_limit(&self) -> u64;
 
     /// Retrieves the gas used by the block
-    fn gas_used(&self) -> u128;
+    fn gas_used(&self) -> u64;
 
     /// Retrieves the timestamp of the block
     fn timestamp(&self) -> u64;
@@ -754,11 +754,11 @@ impl BlockHeader for Header {
         self.number
     }
 
-    fn gas_limit(&self) -> u128 {
+    fn gas_limit(&self) -> u64 {
         self.gas_limit
     }
 
-    fn gas_used(&self) -> u128 {
+    fn gas_used(&self) -> u64 {
         self.gas_used
     }
 
@@ -817,5 +817,17 @@ mod tests {
 
         let decoded: Header = serde_json::from_str(&json).unwrap();
         assert_eq!(decoded, header);
+
+        // Create a vector to store the encoded RLP
+        let mut encoded_rlp = Vec::new();
+
+        // Encode the header data
+        decoded.encode(&mut encoded_rlp);
+
+        // Decode the RLP data
+        let decoded_rlp = Header::decode(&mut encoded_rlp.as_slice()).unwrap();
+
+        // Check that the decoded RLP data matches the original header data
+        assert_eq!(decoded_rlp, decoded);
     }
 }
diff --git a/crates/eips/src/eip1559/basefee.rs b/crates/eips/src/eip1559/basefee.rs
index ebb673f9b8e..895135b7eb8 100644
--- a/crates/eips/src/eip1559/basefee.rs
+++ b/crates/eips/src/eip1559/basefee.rs
@@ -90,7 +90,7 @@ impl BaseFeeParams {
     ///
     /// See also [calc_next_block_base_fee]
     #[inline]
-    pub fn next_block_base_fee(self, gas_used: u128, gas_limit: u128, base_fee: u128) -> u128 {
+    pub fn next_block_base_fee(self, gas_used: u64, gas_limit: u64, base_fee: u64) -> u64 {
         calc_next_block_base_fee(gas_used, gas_limit, base_fee, self)
     }
 }
diff --git a/crates/eips/src/eip1559/helpers.rs b/crates/eips/src/eip1559/helpers.rs
index 5bea1fa2314..a37bac89097 100644
--- a/crates/eips/src/eip1559/helpers.rs
+++ b/crates/eips/src/eip1559/helpers.rs
@@ -24,13 +24,13 @@ use crate::eip1559::BaseFeeParams;
 ///
 /// For more information, refer to the [EIP-1559 spec](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1559.md).
 pub fn calc_next_block_base_fee(
-    gas_used: u128,
-    gas_limit: u128,
-    base_fee: u128,
+    gas_used: u64,
+    gas_limit: u64,
+    base_fee: u64,
     base_fee_params: BaseFeeParams,
-) -> u128 {
+) -> u64 {
     // Calculate the target gas by dividing the gas limit by the elasticity multiplier.
-    let gas_target = gas_limit / base_fee_params.elasticity_multiplier;
+    let gas_target = gas_limit / base_fee_params.elasticity_multiplier as u64;
 
     match gas_used.cmp(&gas_target) {
         // If the gas used in the current block is equal to the gas target, the base fee remains the
@@ -45,7 +45,7 @@ pub fn calc_next_block_base_fee(
                     // Ensure a minimum increase of 1.
                     1,
                     base_fee * (gas_used - gas_target)
-                        / (gas_target * base_fee_params.max_change_denominator),
+                        / (gas_target * base_fee_params.max_change_denominator as u64),
                 ))
         }
         // If the gas used in the current block is less than the gas target, calculate a new
@@ -54,7 +54,7 @@ pub fn calc_next_block_base_fee(
             // Calculate the decrease in base fee based on the formula defined by EIP-1559.
             base_fee.saturating_sub(
                 base_fee * (gas_target - gas_used)
-                    / (gas_target * base_fee_params.max_change_denominator),
+                    / (gas_target * base_fee_params.max_change_denominator as u64),
             )
         }
     }
@@ -125,11 +125,11 @@ mod tests {
             assert_eq!(
                 next_base_fee[i],
                 calc_next_block_base_fee(
-                    gas_used[i] as u128,
-                    gas_limit[i] as u128,
-                    base_fee[i] as u128,
+                    gas_used[i],
+                    gas_limit[i],
+                    base_fee[i],
                     BaseFeeParams::optimism_sepolia(),
-                ) as u64
+                )
             );
         }
     }
@@ -157,11 +157,11 @@ mod tests {
             assert_eq!(
                 next_base_fee[i],
                 calc_next_block_base_fee(
-                    gas_used[i] as u128,
-                    gas_limit[i] as u128,
-                    base_fee[i] as u128,
+                    gas_used[i],
+                    gas_limit[i],
+                    base_fee[i],
                     BaseFeeParams::optimism(),
-                ) as u64
+                )
             );
         }
     }
@@ -189,11 +189,11 @@ mod tests {
             assert_eq!(
                 next_base_fee[i],
                 calc_next_block_base_fee(
-                    gas_used[i] as u128,
-                    gas_limit[i] as u128,
-                    base_fee[i] as u128,
+                    gas_used[i],
+                    gas_limit[i],
+                    base_fee[i],
                     BaseFeeParams::optimism_canyon(),
-                ) as u64
+                )
             );
         }
     }
@@ -221,11 +221,11 @@ mod tests {
             assert_eq!(
                 next_base_fee[i],
                 calc_next_block_base_fee(
-                    gas_used[i] as u128,
-                    gas_limit[i] as u128,
-                    base_fee[i] as u128,
+                    gas_used[i],
+                    gas_limit[i],
+                    base_fee[i],
                     BaseFeeParams::base_sepolia(),
-                ) as u64
+                )
             );
         }
     }
diff --git a/crates/network-primitives/src/traits.rs b/crates/network-primitives/src/traits.rs
index fe8dd988711..244b1c4f7b7 100644
--- a/crates/network-primitives/src/traits.rs
+++ b/crates/network-primitives/src/traits.rs
@@ -153,7 +153,7 @@ pub trait HeaderResponse {
     fn coinbase(&self) -> Address;
 
     /// Gas limit of the block
-    fn gas_limit(&self) -> u128;
+    fn gas_limit(&self) -> u64;
 
     /// Mix hash of the block
     ///
@@ -392,7 +392,7 @@ impl<T: HeaderResponse> HeaderResponse for WithOtherFields<T> {
         self.inner.coinbase()
     }
 
-    fn gas_limit(&self) -> u128 {
+    fn gas_limit(&self) -> u64 {
         self.inner.gas_limit()
     }
 
diff --git a/crates/provider/src/ext/anvil.rs b/crates/provider/src/ext/anvil.rs
index a32d3439258..93733250557 100644
--- a/crates/provider/src/ext/anvil.rs
+++ b/crates/provider/src/ext/anvil.rs
@@ -793,7 +793,7 @@ mod tests {
 
         let latest_block =
             provider.get_block_by_number(BlockNumberOrTag::Latest, false).await.unwrap().unwrap();
-        assert_eq!(block_gas_limit.to::<u128>(), latest_block.header.gas_limit);
+        assert_eq!(block_gas_limit.to::<u64>(), latest_block.header.gas_limit);
     }
 
     #[tokio::test]
diff --git a/crates/rpc-types-eth/src/block.rs b/crates/rpc-types-eth/src/block.rs
index 17fc57def77..1a9afb31f85 100644
--- a/crates/rpc-types-eth/src/block.rs
+++ b/crates/rpc-types-eth/src/block.rs
@@ -80,10 +80,10 @@ pub struct Header {
     pub number: u64,
     /// Gas Limit
     #[cfg_attr(feature = "serde", serde(default, with = "alloy_serde::quantity"))]
-    pub gas_limit: u128,
+    pub gas_limit: u64,
     /// Gas Used
     #[cfg_attr(feature = "serde", serde(default, with = "alloy_serde::quantity"))]
-    pub gas_used: u128,
+    pub gas_used: u64,
     /// Timestamp
     #[cfg_attr(feature = "serde", serde(default, with = "alloy_serde::quantity"))]
     pub timestamp: u64,
@@ -259,7 +259,7 @@ impl HeaderResponse for Header {
         self.miner
     }
 
-    fn gas_limit(&self) -> u128 {
+    fn gas_limit(&self) -> u64 {
         self.gas_limit
     }