When I bought the pump, I could've got a standard pump, a high volume or the high pressure. In my 19 year old wisdom I bought the high pressure. I fully understand pressure is a result of interference in the flow path. That being said I don't know if a high volume with a deeper set of rotors capable of more volume would pump more oil at 60 psi than my high pressure pump did at 75 psi. I had to run an extra quart of oil in the stock pan to keep it from pumping it dry.

I figure the high pressure pump (that I still have) was nothing more than a standard pump with a stiff or shimmed spring.