[chevyIIpost]

The gen 1 SBC has lived through many laps of saturday night circle track racing with standard preasure standard volume stock type oil pumps for many years. It is one of the best stock oiling systems. Blue print/measure/inspect every component. Volume and preasure are tied to each other. One effects the other. If oil temp/viscosity is correct and bearing clearances are reasonable a higher volume pump will just result in more oil being bypassed at the pump at what ever preasure value that the bypass spring is set to. A stock volume pump will provide adequate preasure and volume if the engine is not running excessivley loose clearances and spraying oil all over the place. If you can maintain 60 psi of oil preasure with the oil and engine at operating temps than you have enough volume or preasure would fall off. The SBC does not need higher oil preasure. The rule of thumb is 10 psi per 1000 rpms of engine speed. 60 psi at 6000 rpm. If you use the same 60 psi oil preasure releif spring in a high volume pump you will get to the same 60psi and the same volume of oil to the bearings but the releif valve will be passing that higher volume of oil back into the pan wasting horse power and heating the oil. I beleive the hole high volume oil pump concept came from the early days of engine building when clearances where increased from stock spec to an excessive amount with hopes of making the engine survive in racing enviroments. These increased clearances caused massive leakage from the main and rod bearings and the stock volume pump could not put out enough oil to maintain preasure. The increased clearances where bandaids for other problems with the engine componants and build practices of the times. Bearing clearances are now keep closer to stock allowing a stock volume pump to do the job just fine. If you have preasure you have volume. I would clean up the oil passage alignment between the oil pump discarge and main cap inlet just like port matching intake to heads. Melling and others have had problems with this area. The stock volume pumps I have blue printed will idle at 40 psi and run to 60psi at less than 2000 rpm at full temp.