What oil pump to replace high-volume pump in "recent" rebuild?
The "mechanic" who rebuilt the engine in my '94 wagon used a high-volume oil pump. On cold startup, even running synthetic 0W20, oil pressure is just under 80 psi. (Yes, I have an F-body cluster and yes I have the resistor mod and correct sensor so it shows actual oil pressure, and yes I realize that it's probably not completely accurate.) When accelerating hard, the gauge will jump, then immediately dip to below 60 psi, like the pump is bleeding off pressure or cavitating or something.
Wear metal numbers from 5K-mile oil changes have always been higher than I'd like--not terrible, but not good. The best numbers came from 0W20, the worst from 0W40--I feel like the high-volume pump needs the thinnest oil possible to not have flow issues. Some forum members have suggested switching back to a standard-volume oil pump, and I concur that it sounds like a good idea.
My current shop of choice (not the one that rebuilt the engine), said it would change out the oil pump for $300 in labor, plus parts.
For standard-volume oil pumps, Rockauto has a Melling:
And a Sealed Power:
There are two others but they specifically say "not for high performance or off road", so I'm gonna stay away from those.
Then, under the high-performance heading, Rockauto has literally about 20 different choices from Melling, all of which appear to be some variation of higher volume and / or higher pressure.
So, what oil pump do I want? What other parts will I need? Oil pan gasket, oil, and filter are obvious, but what else?
--'94 Caprice "SS" wagon, 0.30 over, high-volume oil pump, LT4 hot cam, 1.6:1 rockers, ported aluminum Corvette heads, shorty headers, PCM4Less tune, 4.10s, shift kit, side-exit dual exhaust with Flowmasters, OR X-pipe, F-body gauge cluster, Bonneville front and rear seats (working electrics), Bravada console shifter, Bilsteins, 12.7:1 Impala steering box, Boss 338s with 255/45R20s, bunch of other stuff I'm forgetting.
--'04 Mustang Cobra, '15 Audi S4
--1125R, 1050, VMax, VFR800, DRZ-400E