had a 5.7 motor blew replaced it with 5.0 crate motor nothing leaks everthing look fine changed 10 of these never had a problem.normal at startup but falls quickly changed oil pump.
loosing oil pressure on 1998 Chevrolet 2500 Pickup
Do the oil pans and pick up tubes match with the 5.7 and 5.0? Are you verifying the loss of oil pressure with a manual oil testing gauge or are you using the dash gauge which could be off or the sending unit is bad etc? These are GM crate motors?