I just installed a remanufactured early model 350. Before I installed I primed the oil pump,filled the oil filter with oil and filled the engine with 10-30 oil. When I started the engine I noticed the oil pressure was only about 25 or 30 lbs of pressure. I let it run a little while and it lowered to about 10 to 15 lbs. The place I purchased the engine from gave a spec. sheet that said it had been tested and the oil pressure was 62 lbs. Anyone has a clue as to what the problem could be? I thought it maybe a bad oil pump. What do you think?