Just finished rebuilding the top end on my 1990 gmc k2500 with a 5.7 tbi, after reassembling almost everything I wanted to make sure I was getting oil everywhere so I removed a valve cover and tried cranking it with the fuel pump relay unplugged and the main spark plug wire to the distributor from the condenser and watched to see if oil would come up the pushrods.. I cranked it for atleast a few minutes and nothing came up.. I forgot to check the oil pressure gauge though. Would knowing if the gauge read something help to diagnose this or is the problem already obvious