Milodon Aluminum Timing Covers feature either a highly polished face or a CNC machined face. Their rigidity offers a positive non flexing cam stop. Milodon Aluminum Timing Covers are designed to fit over stock and double roller timing chains. Also fits under stock short water pump in most cases(some cases will require only minor water pump modification). Milodon timing covers will not work with 4-gear style gear drives or belt drives.