Made of high-strength forged steel and designed for stock and high-performance custom applicationsSpecial keyed 6° large diameter tapered sprocket shaft that provides more contact area for increased strengthStandard S&S tapered crankpin and pinion shaft are used for ease-of-service8-1/2'' diameter with 4-1/4'' or 4-5/8'' strokeKits come fully assembled, trued and balanced to stock H-D 80'' or 96'' pistonsInclude flywheel, crankpin and connecting rodsMade in the USA'90-'99 application will require pinion shaft conversion kit.