did you smell your oil to see if it has a gassy smell to it there might be a little tear in the diaphram. its a quick pull the dip stick and smell.is there a test for fuel pressure on a car that old.
sorry just ideas im a bodyman by trade lol.a friend of mines grand torinos crank case was full lol and man did it smell like gas.car was running fin i just checked the oil while he was gasin it up lol saved his engine.