no oil pressure

If you are not getting oil pressure up to the lifter galley, then I would check the main bearings also. The lifter galleys are fed off of the mains. Make sure that the holes in the top shell for the main bearings have not spun and cut off the oil feed holes to the lifter galley.

I still think you should check the oil pump first. My gut feeling is that the oil pressure relief valve may have stuck on you. This will cause loss of oil pressure. Remove the oil pump, and take out the cotter pin for the relief valve. Use a punch to make a hole in the cup plug (you don't want to drill it and make metal chips - they will cause it to stick). After you punch a hole in the cup plug for the relief valve, then use a screw to pry the cup plug out - note that the cup plug goes backwards compared to the ones in the water jacket of the block. You need to put the new one in the same direction or your oil pressure will be affected.) You can get a new cup plug in the MP high pressure relief spring kit that costs under $10 at Mancini.

After removing the cup plug, then see if the relief valve will drop out with it turned up side down. Or with a small "hook" tool. It should move easily with minimal resistance. If it is stuck, then there is your problem.