Fits 12 Valve Cummins engine with stock gear housing. Requires factory gasket (not included), can use factory fan with stock 12 valve dampener and belt. Includes Stainless Steel hardware. Allows installation of aftermarket mechanical fuel supply pump. Includes crank seal adapter ring (does not include crank seal). Does not fit first gen trucks (1993 and earlier) fits 1994 and up 12v engines.