Gee Dub

Thanks It what I thought. Just needed confirmation.

I just put this used motor in my 85 GL wagon. Runs fine but I just started to hear engine noise and noticed the oil pressure dropped from 45lbs to 25lbs. I changed the oil thinking it was a plugged oil path. But I still have the problem.It comes and goes. Is the oil pump going out or is it something else? Please help.