COMP Cams Magnum Double Row Timing Set CBFeature induction hardened cast iron Camshaft Gear and billet Steel crank sprocket. 3 keyway crank sprocket for 4 degree incremental adjustability, 4 degree maximum advance retard. Heavy duty, heat treated double row timing chain Catalog User 1 This Part Fits: Year Make Model Submodel 1963,1965 1975 Chevrolet Bel Air Base 1963,1965 1972 Chevrolet Biscayne Base 1973 Chevrolet Blazer Base 1972 Chevrolet Brookwood Base 1978 1980 Chevrolet C10 Big Ten