The best way to test oil pressure is by installing a mechanical gauge. The King Seeley (sp?) unit that KF used is known for erratic readings. To answer your question, yes, KF engines are prone to oil pressure issues. The oil pump uses a cast iron housing with a stamped steel base cover. When they wear, the stamped base cover stretches and allows oil to escape, thereby dropping pressure. Your car should have about 20lbs at idle and 35lbs at 35 mph, both with a warm engine. So, stop by and worthwhile auto parts store and buy a mechanical gauge. Remove the existing sending unit ,install the new gauge somewhere under the dash and run the line directly to the opening in the block where the old sending unit was and then you can observe the readings as you run down the road.
As for the erratic fuel gauge readings, it's almost always the fault of the tank unit. Either you have an iffy ground or the unit itself is going bad.