Just got my rebuilt engine out of the shop it's showing low oil pressure. I bought the mechanical oil gauge and its only showing about 4-6 psi. Ive already dropped the oil pan and the pickup tube looks good. I'm starting to think its the oil bypass? Anyone have a diagram or some advice to help me troubleshoot this problem? Also truck has new oil filter and new oil pump. I read somewhere to remove the oil filter to help it prime and it seems to be squirting out a good volume of oil. Does anyone have a diagram of the oil cooler also?Thanks in advance