I had a mechanical autometer gauge that was almost new. and I think it had around 40 psi when driving. and as soon as I punched on the gas and the rpm's went up it would start loosing oil pressure. I don't remember what it was at idle but remember that it seemed to be normal or similar to my other cars, my dart.
a few months before this started happening the motor sat un started for about 4 years, then I pulled the old 2 barrel carb off and put a 750 holley on it, because that is what I had . and pulled out the automatic trans and put in a 4 speed. it never got run hard the whole time I had the auto trans in it and even after I put the 4 speed in I don't think it ever saw over 5000 RPM.