COMP Cams 2138 Magnum Double Roller Timing Set for Ford 5.0L and 351 Windsor, '84-'92 Feature 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 true double roller timing chain; chain available separately Ideal for mild street performance applications