Low oil pressure on these motors is often caused by bad cam bearings. But your running oil pressure is not too far off from normal. I suspect your noise is a rod knocking. Some folks suggest using a stethescope to listen to the engine, or a piece of fuel hose, touched to the motor at or near each cylinder. Others say you can pull the spark plug wires one at a time until the noise softens. If you catch the problem early enough you may be able to pull the oil pan and adjust the offending rod. Do you have a shop manual?? If not, get one. If your rods have not been adjusted too many times before there will (should) be some shims on the rod cap bolts between the rod and cap. You can take out 1 or 2 shims from both sides and put it back together. Even the shop manual calls the rod bearings "selective fit". It's really a trial and error method to determine if the rod is tight enough. It should not bind on the crank or be sloppy. You should be able to snap the rod back and forth along the crank bearing journal with thumb and forefinger. Hopefully the crank has not been scoured too much. Good luck.

Professional Novice