I mentioned most of this in post #30. If you have cold reading of 60psi then you likely do not have a relief valve issue. You did not mention if this was at idle. If its at high rpm there could still be an issue.Thank you so much. You've really helped me understand. Have a previous shop owner coming over tomorrow and we can discuss your info. Thanks for taking the time to give me the information.
Big blocks can have drain back issue and crankcase venting issues- but more in aluminum race blocks without cross drilled main feed and grooved bearing you would have oiling issues - not oil pump related pressure issues per se. The valley drain back holes are small and the oil hit the cam on the way back to the pan where the oil spray and crankcase ventilation can further impede drain back- again more in race blocks /cold oil.
What is the fully warned up oil pressure gauge reading at each rpm step from 1000- 4000 rpm?
Also, is the engine noisy or quite when fully warmed?
- Ken