Right on BOB,Have always run stock MELLING GM replacement oil pumps currently have one in my 454BBl (50PSI from start up to shutdowne) run NAPA 10W40.old man runs same pump in his 468 BBL 1967 nova car runs 9,50's 1/4 136/137 MPH. SO at what point do you need a high valume pump I dont know. any way JOHNNY if it's going to keep you up at nights,spend $20.00 for a MELLING stock pump and forget about it.(FYI) If your pick up dosn't bolt to pump housing,after you install it have it MIG- welded to the pump,you run the chance of it falling off down in to the oil pan after a good hole shot,That will realy freak you out (NO OIL PSI)talking from first hand experience.