When installing an oil pump in a big block Chevrolet, it is essential to make sure the oil pickup has not moved and is still tight so that it will sit at the lowest point in the oil pan. Oil pumps are available in two categories: high pressure or high volume. High pressure is not normally used except in high performance applications; however, high volume is desirable for better lubrication, especially on a high mileage vehicle.
Clean off the mating surface for the pump on the rear main bearing. Fill the pump with STP oil treatment to keep it primed for start up. Rotate the shaft as the STP is poured into the pump.
Install the oil pump driveshaft rod on the end of the oil pump's short shaft. Make sure the retainer cover is pulled down enough to cover the mating surface between the driveshaft and oil pump rod.
Insert the oil pump driveshaft into the distributor shaft hole above the main bearing oil pump mounting surface. Continue to lift the oil pump until its seat contacts the rear main bearing cap. Make sure the locating stud fits into the base of the pump. Insert the bolt and tighten it securely with the appropriate socket. The pump does not use a gasket between the mating surfaces.
