Like Tom said, cut open the filter and inspect,then
oil change and double check the
oil pressure gauge....sounds very odd.......
what kind of
oil pump do you have???
I'm running a road race Canton 8 quart pan on a small block Ford in my 65 coupe road race car, I've tried to watch the oil pressure is some long sweeping turns and have never seen my oil pressure fluctuate at speed, normal oil pressure at speed is from 50 to 55 psi, with the oil temp from 220 to 250......The canton pan has the 4 spring loaded trap doors and evidently does a good job at keeping the oil in there for the pickup...I'm running a Melling HP Series standard volume/standard pressure pump......
David