454 oil pressure?

[johnathan]

The oil pressure on my big block reads 50 psi+.This is a bone stock 454.There is a slight rise as I rev it. Now,the other morning I crank her up and its reading much lower 15-45 psi. with much larger fluctuation as I gas it.I pull it around the yard shut it down and then when I crank it back up ,back to 50 psi. Would this indicate bad oil flow?This is a good quality manual guage. Now I have a squeeking noise coming from the back side of the motor weeenk weeeenk?

 

[Thunder]

How old is the oil filter? Mabe it is clogged and the oil bypass valve is opening. Is it a fram? Fram filters are notorious for causing the oil bypass valve to open and drops in oil pressure.