EN40B billet steel, rated over 3000whp. All cranks are stress relieved, shot peened, magna flux inspected and nitrided (multi step heat treatment) for ultimate performance. Fully profiled counterweights are designed for reduced windage through the crankcase creating less oil resistance for better rpm potential. Features straight-shot, priority main oiling. This crankshaft requires internal balancing and the ATI Super Damper #918659 - do not reuse the OEM external damper.