My 1969 corvette 427/390 is around 35-40 when warmed up. It’s has 3:08 gears. Rob

If it is an electric gauge, make sure the lead is not grounding out somewhere ... I think if the lead is grounded ... the gauge will indicate max pressure. If I am wrong -- someone chime in ... TAZ

The gauge is a mechanical unit.

gauge
 

Sent you a PM regarding the rebuilding / clean-up of the pivot points.

Finally got around to removing the oil pressure gauge; can anyone here help guide me through the steps needed to get it working properly again? Nothing about the gauge seems broken, I can move the needle very easily and it doesn't seem to stick at all.

Of course that makes me think it's something more serious...............ugh.

Oil pressure pegged
 

Try looking at the oil filter bypass valve above the oil filter, maybe the bypass valve is clogged or stuck shut thereby raising the oil pressure, just a thought, without pulling the engine. Don.

The bypass is only supposed to open when the oil filter is clogged.

'

Have you tested actual pressure w/ a remote gauge yet also how long has the engine been operating normally - any recent rebuild etc?
Info supplied so far sounds like it may be the pressure relief valve in the pump as Bill mentioned at the beginning?:hmmm:
So, best test before going in other directions and good luck w/ everything!
:beers:
~ Pete

.

Oil pressure pegged
 

The oil pressure bypass valve also opens when the engine oil is cold so that the oil filter will not expand. Racers have been plugging off this bypass valve opening for years but are cautious about revving the engine when cold to prevent oil filter damage. When the engine is totally warmed up is the oil pressure still pegged? If so I'd check the oil pump pressure spring, cup and relief valve in the oil pump. If pressure goes up there is a restriction somewhere. Doesn't cost anything to check it out. Just my 2 cents worth. Don.

Not true. At least with sbc & bbc. The bypass valve (BV) opens @ 17-18 lbs of pressure. The engine, while running, is constantly by-passing oil from the filter. In other words, while the engine is running, a % of unfiltered oil is always going through an engine. It was designed that way and that bypass should never be plugged. The engineers that designed the oiling system felt it was better to have some dirty oil, than no oil at all.
Back to the OP. There are only 3 causes of pegged oil pressure I am aware of 1) defective gauge- get another gauge and test to rule out gauge 2) stuck pressure relief valve in oil pump- remove pump repair or replace ( 2nd option preferable) 3) oil galleys plugged with foreign matter-tear down engine.