2004.5-2010 GM 6.6L Duramax CNC Ported Cast Iron Cylinder Head (One Head) LLY/LBZ/LMM 2021-chevrolet-express-4500-6-6l-v8-gas-esi5444970 When installed

When installed

This custom fabricated kit uses 304 stainless steel

Convenient 25-meter bulk roll

6L Duramax with the superior combination of PPE Manifold with 304 Stainless Steel Up-Pipe Kit

2004.5-2010 GM 6.6L Duramax CNC Ported Cast Iron Cylinder Head (One Head) LLY/LBZ/LMM 2021-chevrolet-express-4500-6-6l-v8-gas-esi5444970 When installedDuramax Ported Cast Iron Cylinder Head 2004. 5 2010 GM 6. 6L (One) LLY LBZ LMM 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.