The OEM Duramax cast-aluminum cylinder heads fall short over time - the different heat expansion rates between cast-iron engine block and cast-aluminum cylinder head cause head gasket scrubbing, and eventually blown head gaskets. The aluminum cylinder heads are also prone to warping, melting, and/or cracking in high-performance applications where excessive heat is introduced.

PPE’s new ported Cast Iron Cylinder Head is the ultimate upgrade to your Duramax engine and eliminates any head gasket or cracking concerns. Cast from high-quality alloyed gray iron, the PPE Cylinder Head offers elevated fatigue strength, heat, and creep resistance, which prolongs the cylinder head’s lifespan significantly. PPE Cylinder Head also shares the same heat expansion rate as the stock cast-iron cylinder block - no more blown head gaskets.

Our CNC porting process improves airflow, enhancing power, fuel efficiency, and throttle response while reducing engine stress and turbo lag. By smoothing the ports and maintaining wall thickness, these heads provide increased horsepower and torque without sacrificing reliability. Tailored to each specific head, the CNC machining compensates for casting variations, ensuring consistent and optimized airflow dynamics. Whether you have a damaged aluminum cylinder head or a desire for better reliability and longevity on your Duramax engine, the PPE Cast Iron Cylinder Head is undoubtedly the best choice.

Important Note: The valve seats of the PPE Heavy Cast Iron Cylinder Heads are installed with an interference that maximizes the durability and lifespan of the cylinder heads. Such interference might not be optimal for extreme-performance applications where a significant amount of heat is created. For those applications, PPE suggests that the exhaust valve seats be replaced with higher interference (+0.006 inch to +0.008 inch) oversized exhaust valve seats (Nominal size 34mm).

Requires the use of LBZ/LMM glow plugs on LLY engines
Features:

• Specially alloyed gray cast iron liquid-cooled cylinder head
• 5-Axis CNC ported intake and exhaust ports for smooth, unrestricted airflow
• Increased thermal efficiency compared to aluminum heads
• Reduced noise and vibration, better ride
• Eliminates head gasket scrubbing issue (blown head gasket)
• Higher fatigue strength and heat resistance
• Premium 21-4N, Stellite-reinforced exhaust valves
• Fully nitridated valves, better abrasion resistance
• Ready to install - comes with all valvetrain components, rocker arm dowels, and freeze plugs