Planning on pushing the power levels of your Duramax engine? Whether you are starting on a full rebuild or just upgrading it's important to add strength and quality to the one place where you need it most: the engine! Industrial Injection's Remanufactured Heads for the Duramax LLY are a great place to start because every LLY Duramax cylinder head goes through a comprehensive remanufacturing process to ensure durability, performance, and reliability that meets or exceeds OEM standards. SOLD AS A PAIR.

Precision Cleaning & Inspection Process

Each head is first jet washed in a high-pressure spray cabinet to remove oil, debris, and contaminants. The head is then glass beaded to eliminate carbon buildup and restore a clean surface.

After cleaning, the head undergoes a detailed inspection process including magnaflux testing (for cast iron heads) or pressure testing to check for cracks and structural integrity. Finally, technicians perform a visual inspection for defects that could affect performance or reliability.

New high-strength alloy, heat-treated iron valve guides are installed in every remanufactured Duramax head. These guides are heat treated to Rockwell 22 “C” scale, delivering exceptional durability and wear resistance that exceeds many factory materials, including bronze guides.

Each valve guide features a precision spiral groove designed to retain oil and improve valve lubrication during engine operation, helping extend engine life.

Upgraded Heat-Treated Valve Guides

These LLY Duramax heads receive new high-strength alloy valve guides that are heat treated to Rockwell 22 “C” scale for maximum wear resistance.

Diamond Honed Valve Guide Precision

Unlike traditional reaming, the valve guides are precision honed using diamond abrasives to achieve exact tolerances. This process guarantees consistent guide diameter and geometry, superior surface finish, and precise valve alignment.

Multi-Angle Valve Job for Improved Airflow

Each remanufactured head receives a precision multi-angle valve job using a Serdi 100 guide and seat machine.

This advanced machining process:

• Simulates the true valve stem alignment
• Ensures a perfect valve-to-seat seal
• Helps maximize airflow in and out of the cylinder head

Improved airflow can support better engine efficiency and combustion performance.

Precision Machined Cylinder Head Surface

The cylinder head deck surface is machined using CBN or diamond tooling on a Berco milling machine.

This allows precise control of the surface finish to ensure compatibility with various head gasket types, including:

• MLS (Multi-Layer Steel) head gaskets
• Performance gasket materials

A properly machined surface helps ensure reliable sealing and long-term engine durability.

Final Assembly

After machining is complete, each LLY Duramax remanufactured cylinder head is:

• Jet washed again for final cleaning
• Thoroughly dried
• Carefully assembled with new valve seals and valve springs

The result is a high-quality stock replacement Duramax cylinder head designed for dependable performance.