The OEM Duramax cast-aluminum cylinder heads fall short over time - the differing heat expansion rates between the 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 LB7 Cast Iron Cylinder Head is the ultimate upgrade for your Duramax engine, eliminating any concerns about head gaskets or cracking. Cast from high-quality alloyed gray iron, the PPE Cylinder Head offers superior fatigue strength, heat resistance, and creep resistance, significantly prolonging its lifespan.

The cast-iron material also shares the same heat expansion rate as the stock engine block, eliminating blown head gaskets. Additionally, the PPE Cylinder Head features cast-in fuel injector cups, solving the OEM injector cup leaking issue.

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 seek better reliability and longevity for 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 (Plus 0.006 inch to Plus 0.008 inch) oversized exhaust valve seats (Nominal size 34mm).