ARP 1547905 Heavy-Duty Oil Pump Driveshaft Kit For Select Ford 351C, 351-400M Applications Extra heavy-duty oil pump driveshaft can help you avoid expensive engine damage Designed for increased capacity oil pumps or heavy viscosity lubricants Shaft has larger diameter than the OEM unit Made from premium grade ARP2000 chrome moly steel and heat-treated to 220,000 psi CNC milled (not broached) hex; retaining washer is installed