diff --git a/crates/primitives-traits/src/block/mod.rs b/crates/primitives-traits/src/block/mod.rs
index 4c98a94b3..f161ced82 100644
--- a/crates/primitives-traits/src/block/mod.rs
+++ b/crates/primitives-traits/src/block/mod.rs
@@ -88,3 +88,29 @@ where
         (self.header, self.body)
     }
 }
+
+/// An extension trait for [`Block`]s that allows for mutable access to the block's internals.
+///
+/// This allows for modifying the block's header and body for testing purposes.
+#[cfg(any(test, feature = "test-utils"))]
+pub trait TestBlock: Block {
+    /// Returns mutable reference to block body.
+    fn body_mut(&mut self) -> &mut Self::Body;
+
+    /// Returns mutable reference to block header.
+    fn header_mut(&mut self) -> &mut Self::Header;
+}
+
+#[cfg(any(test, feature = "test-utils"))]
+impl<T> TestBlock for alloy_consensus::Block<T>
+where
+    T: SignedTransaction,
+{
+    fn body_mut(&mut self) -> &mut Self::Body {
+        &mut self.body
+    }
+
+    fn header_mut(&mut self) -> &mut Self::Header {
+        &mut self.header
+    }
+}
diff --git a/crates/primitives-traits/src/header/sealed.rs b/crates/primitives-traits/src/header/sealed.rs
index ef8b5fde5..4291735a6 100644
--- a/crates/primitives-traits/src/header/sealed.rs
+++ b/crates/primitives-traits/src/header/sealed.rs
@@ -119,6 +119,24 @@ impl Decodable for SealedHeader {
     }
 }
 
+impl<H> From<SealedHeader<H>> for Sealed<H> {
+    fn from(value: SealedHeader<H>) -> Self {
+        Self::new_unchecked(value.header, value.hash)
+    }
+}
+
+#[cfg(any(test, feature = "arbitrary"))]
+impl<'a, H> arbitrary::Arbitrary<'a> for SealedHeader<H>
+where
+    H: for<'b> arbitrary::Arbitrary<'b> + Sealable,
+{
+    fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
+        let header = H::arbitrary(u)?;
+
+        Ok(Self::seal(header))
+    }
+}
+
 #[cfg(any(test, feature = "test-utils"))]
 impl SealedHeader {
     /// Updates the block header.
@@ -152,24 +170,6 @@ impl SealedHeader {
     }
 }
 
-impl<H> From<SealedHeader<H>> for Sealed<H> {
-    fn from(value: SealedHeader<H>) -> Self {
-        Self::new_unchecked(value.header, value.hash)
-    }
-}
-
-#[cfg(any(test, feature = "arbitrary"))]
-impl<'a, H> arbitrary::Arbitrary<'a> for SealedHeader<H>
-where
-    H: for<'b> arbitrary::Arbitrary<'b> + Sealable,
-{
-    fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
-        let header = H::arbitrary(u)?;
-
-        Ok(Self::seal(header))
-    }
-}
-
 /// Bincode-compatible [`SealedHeader`] serde implementation.
 #[cfg(feature = "serde-bincode-compat")]
 pub(super) mod serde_bincode_compat {
diff --git a/crates/primitives-traits/src/header/test_utils.rs b/crates/primitives-traits/src/header/test_utils.rs
index 0e79f6cb4..58237fbca 100644
--- a/crates/primitives-traits/src/header/test_utils.rs
+++ b/crates/primitives-traits/src/header/test_utils.rs
@@ -1,10 +1,45 @@
-//! Test utilities to generate random valid headers.
+//! Test utilities for the block header.
 
 use alloy_consensus::Header;
-use alloy_primitives::B256;
+use alloy_primitives::{BlockHash, BlockNumber, B256, U256};
 use proptest::{arbitrary::any, prop_compose};
 use proptest_arbitrary_interop::arb;
 
+/// A helper trait for [`Header`]s that allows for mutable access to the headers values.
+///
+/// This allows for modifying the header for testing purposes.
+pub trait TestHeader {
+    /// Updates the parent block hash.
+    fn set_parent_hash(&mut self, hash: BlockHash);
+
+    /// Updates the block number.
+    fn set_block_number(&mut self, number: BlockNumber);
+
+    /// Updates the block state root.
+    fn set_state_root(&mut self, state_root: B256);
+
+    /// Updates the block difficulty.
+    fn set_difficulty(&mut self, difficulty: U256);
+}
+
+impl TestHeader for Header {
+    fn set_parent_hash(&mut self, hash: BlockHash) {
+        self.parent_hash = hash
+    }
+
+    fn set_block_number(&mut self, number: BlockNumber) {
+        self.number = number;
+    }
+
+    fn set_state_root(&mut self, state_root: B256) {
+        self.state_root = state_root;
+    }
+
+    fn set_difficulty(&mut self, difficulty: U256) {
+        self.difficulty = difficulty;
+    }
+}
+
 /// Generates a header which is valid __with respect to past and future forks__. This means, for
 /// example, that if the withdrawals root is present, the base fee per gas is also present.
 ///
diff --git a/crates/primitives-traits/src/lib.rs b/crates/primitives-traits/src/lib.rs
index c5d9b710c..bad587e0f 100644
--- a/crates/primitives-traits/src/lib.rs
+++ b/crates/primitives-traits/src/lib.rs
@@ -74,8 +74,6 @@ pub mod sync;
 
 /// Common header types
 pub mod header;
-#[cfg(any(test, feature = "arbitrary", feature = "test-utils"))]
-pub use header::test_utils;
 pub use header::{Header, HeaderError, SealedHeader};
 
 /// Bincode-compatible serde implementations for common abstracted types in Reth.
@@ -135,3 +133,11 @@ pub trait MaybeSerdeBincodeCompat {}
 impl<T> MaybeSerdeBincodeCompat for T where T: crate::serde_bincode_compat::SerdeBincodeCompat {}
 #[cfg(not(feature = "serde-bincode-compat"))]
 impl<T> MaybeSerdeBincodeCompat for T {}
+
+/// Utilities for testing.
+#[cfg(any(test, feature = "arbitrary", feature = "test-utils"))]
+pub mod test_utils {
+    pub use crate::header::test_utils::{generate_valid_header, valid_header_strategy};
+    #[cfg(feature = "test-utils")]
+    pub use crate::{block::TestBlock, header::test_utils::TestHeader};
+}