Anyone try one of these oil pumps just curious

 

I have never heard of them but then there is a lot of stuff I have never heard of. To say they are pricey would be an understatement. Hard to beat a good Melling pump.

 

Yup, I use one. It's a blue printed melling. Is it worth it? I dunno.
They buy batches and mix/match housings and gears to get the best side clearance. Then they mill the housing to get the best top/bottom clearance. The bottom gets milled flat. They also drill holes in the bottom of each gear tooth - I assume that's a cavitation thing. The one I got several years ago had the green spring with a bolt spacer instead of using the pink spring Melling now supplies. Oh, and they replace the bypass spring retention carter pin with a tiny bolt and two nuts.
The large bypass one has some other modifications to it.
You can also just get a Melling and check clearances yourself, and exchange if you don't like it. It's always a good idea to thoroughly inspect and clean parts anyway.

 

What is your oil pressure at running temp and what are your clearance if you don't mind

 

It's too bad the "Internal Bypass" version is so expensive, the lesser priced version is plenty expensive enough !

 

FYI there's also: Precision Oil Pumps.

 

Mains around 3, rods around 1.75, I think it has 10w30 in it right now. ~70 psi cold, ~20 psi hot idle

This threw me for a loop. The stock Olds design *IS* an internal bypass. So the more expensive one is where they've modified the bypass in some way to handle more volume.

Fun story: this is now permanently in my brain because I was chasing a low oil pressure problem last year. Finally spun up the oil pump with the distributor out to find that I had an *external* oil bypass. Back when the block was machined, the operator sent the boring bar too low and it cut into the main oil feed galley leaving a pea size hole. At the time I didn't know what was going on so assumed it was splash from the oil pump or something. That was fun to fix.