Just got my first slant six

Ok so I went back and started over. I replaced the spark plugs and the valve cover gasket and I cleaned up the engine. I learned that I didn't properly have the throttle wide open (the choke was) during the first tests and my battery wasn't fully charged either. I checked compression again after fixing those issues. This time I had 85-95 on all six cylinders. I know that is lower than what everyone has said it should be, but it runs great so I am thinking the gauge might be the issue. I then attempted to determine why it has VERY low oil pressure causing the light to come on. I installed a manual gauge and found it idling at about 4psi! I was only able to get it up to around 20psi at higher RPM. I removed the pan and oil pickup and found what appeared to be hard carbon deposits and white nylon gear teeth blocking most of the pickup. I believe the timing gear issue was handled years ago by the previous owner according to the stack of service records that came with the car. I am guessing no one has ever taken the pan off. I thoroughly cleaned the pickup and the pan. The pickup tube had no cracks or tool marks. I put everything back together and the manual gauge still showed about 4psi at idle. I removed the oil pressure relief valve spring and added a washer to the end as suggested by other members. That changed nothing. I ordered a new oil pump and I am waiting to replace the old one. Hopefully that solves the oil pressure problem. Once that is done, the car is ready to sell if anyone is interested.