The Empire Performance Engineering BILLET Duramax main caps are precision machined from hardened 4140 chromoly steel instead of the lower quality 1045 steel used by competitors. Using the latest 3D CAD software in conjunction with OEM GM data we developed these main caps out of necessity for our Drag Race and Sled Pulling engines and find them to be applicable in most street engines. With the increased boost levels seen in big single and larger twin turbo setups, the factory crank pushes down on the caps often leading to stress fractures and cracks. The factory main caps were not designed for the forces required when doubling and tripling the factory horsepower and torque levels. These caps are included in our short block and race engine packages and now available separately for those building their own engines.
They will accept factory oil pick up tubes and are tapped to use a puller for easy removal. MACHINING IS REQUIRED WHENEVER CHANGING MAIN CAPS. Compatible with factory bolts or aftermarket ARP main studs and side bolts. Our BILLET main caps are the strongest most rigid replacement caps on the market. WIth the use of these billet main caps you will NOT need a girdle.