My take on the oiling system crossover tube for the small block

Duane said
So there is a 10 psi drop after the filter? Your line pressure is actually dropping as the rpm got higher which is not good. 37psi at 5,000 rpm is not good.imho

We can't automatically make this conclusion on the pressure drop; you gotta account for the possibility that the 2 separate gauges are reading differently; the one at the 'line psi' location just may be off.

Some SMALL drop at the normal oil pressure sensor point ('line psi' in the data) with RPM is to be expected. Once the pressure relief spring starts limiting the pump outlet pressure, then the pressure at the top of the passages into the passenger side gallery is subject to the flow through the engine; that flow gradually increases with RPM, and will drop the pressures into the gallery a bit due to flow resistance in the filter and the passages to/from the filter. The 'line psi' difference 3k to 6k RPM is -2 psi; seems pretty good to me.

OP, what filter are you using?

mopardude318 said
I have a HV pump on the engine right now. Haven't done anything else to it, no HP springs, no shims. Stock out of the box Melling HV pump from Napa.
Take a look.
Precision Oil Pumps

From the data for 'oil psi', it is pretty obvious that you have the 50-ish psi relief spring with the present HV pump. So if the new pump is shimmed up to around 70 psi, then you ought to see a big change.

I 'took a look' yesterday at that site.. it did not say anything to help understand this.