The only knock I know of against high volume pumps is that if the engine is "tight" enough where it doesn't bleed off a lot of oil when it's running, sometimes the pressure relief valve can't flow enough oil to control the pressure.
Most of the stock type HV pumps cant flow enough
by-pass if the engine is tight.. it gives high
pressure even while its by-passing... I have
tried to open up the by-pass but for myself it
didnt matter because I run .003/.003 on all my
junk... but usually with a tight engine and thick
oil it wont by-pass enough... he started out with
a 100psi cold and as it warmed up it dropped to 75..
myself I would never want more than 70psi even cold
