How much oil pressure do you really need?

[Lexstang]

The idiot light flickers and the oil pressure shows pretty low 20psi on my 81 400m. It has been like this for a while(though it isn't a daily driver now) I doesn't smoke has plenty of power, the lifters never ever tap or rattle. I replaced the oil pump and that didn't change a thing. Should I go for heavier oil than 10w40? I do need a rear main seal, but should I do something else?

No valve stem seals are listed for it on summit racing but if you look the seals up without the specific vehicle or motor lists a bunch of sizes. I am going to replace cam, lifters, springs, pushrods, retainers, timing set, intake, carb, headers and exhaust. I will probably pull heads because I think I am going to have a VERY hard time getting exhaust manifolds off. Do you have to have special tools for the stem seals? Anything I might need to check while they are off? Truck runs great now but that edelbrock performer package looks like wicked gains. Got the cam on ebay for 52 dollars today instead of 155. Though it did take 2 years to come up and win.

[Timido]

The best way is to check the oil pressure with a real oil pressure guage. The idoit light could be wrong. If it is 20psi at Idle warm I wouldnt worry about it. If you need a new rear main anyway and the oil pressure is low put a new set of bearings in it.

[RIXXX93GT]

Yep what he said, sounds like your going to have the motor stripped anyway, get your crank polished and throw some bearings in it, thats most likely where your psi went from worn bearings. 20 psi is not very concerning to me on a street car with miles on it especially one thats warmed up. Heavier weight oil isnt the answer.

[Lexstang]

I do have a gauge a cheap one from autozone. But I had read somewhere that the bearings caused the psi loss. I originally planned on trying to replace that rear main in the truck, but I guess it would solve both problems at once without too much extra work. I guess with as far apart as I will have it I need to actually check the compression, though I think it is ok, and see if I need to throw in a rebuild kit all at once.