Chain is rugged, double-row type with oversized 0.250 in. rollers that deliver long life and reliability Fits: 390/427/428 FE Engines Full roller chain with 9-position multi-index crank sprocket. The crank sprocket has 2 degree increments for timing adjustment of up to 8 degrees retarded, 8 degrees advanced, or straight-up (no advance or retard). Cam sprocket is made from cast iron. Crank sprocket is made from induction-hardened, billet steel Chain is rugged, double-row type with oversized 0.250 in. rollers that deliver long life and reliability