understanding a low oil pressure 360
What were the actual bearing clearances when you assembled the engine?
That’s what we need to know. What are the clearances and what lifters is he running.
As for the plugs…the plugs that go into the lifter galleries don’t do ****. I never ever use them. If the oil leaks around the plate a little so be it. As long as the cam plate is on it will make pressure whether or not those plugs are in there.
The plug under the oil pressure port will not change oil pressure if it’s left out. Not a single pound of pressure will change if that plug is in or not.
It does change the way the oil is filtered though and it needs to be in for that reason.
I’m not standing in front of a block but IIRC the plug under the right angle adapter can be out and you don’t lose pressure. You just allow dirty oil to bypass the filter. Not good but not a pressure loss.
The other plug is the one that blocks the rear of the drivers side lifter gallery. It has to be in there. You access it from the back of the block and you remove the plug at the bell housing to gain access to that plug.
You can pull the distributor and see if that plug is there. If it’s not, you can with much patience and maximum swearing get that plug in through the distributor hole. Worse case scenario is you have to pull the intake to get to it, but it can be fixed without dropping the gearbox.
Oil leakage at the rods is controlled by the diametrical oil clearance. .0035 on the rods will leak more oil that .0020 will at the exact same side clearance. That’s the FACT.
Rod side clearance should be no less than .025 but good luck getting it. The rods are too wide as it is.
Rod side clearance isn’t your issue and neither is the 20 grade oil.