Oil pressure too high?

is there any way to see if the relief valve is stuck? Or is that something you have to put in a new oil pump?

Out of curiosity what weight oil are you guys running? Do you think the 15-40 Rotella T is too thick for my 360? I've been using it since the diesel oil has the good additives for old school engines. I've ran it in my '71 Honda 750 motorcycle for 6 years after the rebuild and its great stuff.

(haha now I'm going to get all the oil science guys to reply)