Times 2, 30-35 psi is perfect for a 25 plus year old motor. Don't change a thing.
Many guys think the higher number / thicker oil is better, but that isn't actually true for a street car.
In many cases, the "thicker" oil actually causes stress / strain on motor components like oil pump drives etc. ,
You've been doing it right for 25 + years - keep up the good work!