360 oil pressure.. is... low

Engine had a rusted fran filter.. oil was sludge..   engine pinged on 87.. and im sure they only put 87 in it.   I fixed everything on this Jeep.. leaf springs. Shocks. Rusted panels. Floors. Rusted frame rails.  Dropped gas tank repaired skid plate.. its in great shape now.  Looks great runs great minus the exhaust manifold and rear main leak that just aont stop fing leaking.

The heads when i took the valve covers off when i got it 6 years ago had thick butter like sludge inside i could scoop eith my fingers.   Oil pan did too.  But now its clean as a whistle

But the crank abd pistons looked fine.   The bearings also looked great... still silver.. even foggy still like theyre new bearings.   Oil pressure back then was 50psi driving hot.  And 30 idle in park at 1000 rpm.   And in gear at 650 rpm it was always around 20 psi.

Fast foward it has 150k miles now.   Still runs great drives great... i attempted my rear main seal a 2nd time.. still leaks of course.. but the bearings again still silverly looked good to me.  No copper.   My oil pressure though is low.

Hot idle in 650 rpm its below the first notch.  So 10psi or lower.  Hot idle in park 1000 rpm its 20-25 psi.   Driving its 45psi.  Doesnt go higher so 45 at 2000-3000-4000 rpm.

Is this engine done with oil pressure this low ?  Or what ?   Lile i said it drives fine.  Doesnt vibrate..  knock.  Tick.  Or have loss of power.

I will check compression again later but 4 years ago it was 150 accross the board.. but cylinder 8 was like 130.. Oh im using 10-30.  Thinking of switching to 10-40...  Its an amc 360 btw

I wouldn't sweat the compression either, can be hard to get good accurate results with this test.

By all means rebuild it if you are looking for an excuse to do so, otherwise drive on I reckon.

one easy trick to increase oil pressure at idle is to increase idle speed. not saying it

fixes the problem, but it works!

25+ years ago these were the go to for farmers in the area hauling family and livestock trailer.

Change the intake for a 4 barrel square bore and 600 CFM carburetor were first. Started with Holley's but they started producing poor carburetors back then and Edelboock's were the next go to. Now there are lots of choices.

This provided the biggest HP gain and more MPG at the time.

The factory camshaft in those is what really holds you back. That was next when the engine needed freshening.

Dual exhaust was in there also. 

Headers were never a thing as farmers wanted reliability, never raced, and headers at the time would not last long on gravel roads, in fields, through winters and running past the transfer case was a pain also.

Headers were for the CJ crowd that were mud racing on weekends.

Should add that we only had one speed shop within 50 miles and one farm/automotive machine shop. Balancing anything was done at the tire shop! There was no internet, just catalogues. He was an authorized Crane and Holley dealer and if you wanted a camshaft it was going to be a Crane and a Holley carburetor, until he got fed up with returns and started supplying Edelbrocks. Had a choice of 450, 600 or 750 CFM 4 barrel Carburetor, manual or electric choke. You had to drive 100+ miles if you wanted anything "different". His brother was the local wrecker, so 4 barrel intakes were a phone call, usually coming off cars. I had a standing order of one for my horde. Did do some Carters on 4150 intakes, but they were more work modifying an adapter, but worked well enough.