Many an engine has been destroyed as a result of oil pump driveshaft failure. To cure this all-too-common problem, ARP has designed an extra heavy-duty shaft that will provide you with the necessary reliability. The shaft is made from premium grade ARP2000 chrome moly steel and heat-treated to 220,000 psi. The shaft diameter is a larger diameter than the OEM unit, features a CNC milled (not broached) hex, and has the retaining washer installed. These features combine to enable ARP shafts to handle the added torque requirements of increased capacity oil pumps or heavy viscosity lubricants.