I installed a 1998 LS1 from a wrecked corvette in my 69 Camaro - http://lees69camaro.com/after.htm and have low oil pressure. I have an after market Pan and pick up. I was told it was likely the "O" ring for the pick up. I recently removed the trans and bell housing, raised the motor about 2 inches and got the pan off. I then replaced the pump with a moroso along with a new "O" ring. The pump came with 2 "O" rings. A black one and a green one. I used the black one as it seemed to fit best. I attached the pick up to the pump with the bolt tight. Then I slid the pump on and tightenen it. The rear bolt at the sump lined up perfect. I thought my problem was resolved. After filling with 5.5 qts of Mobil 5-30 syn I fired it up. 50 psi at idle. All great. On a test drive while it warmed up the pressure dropped. At full temp my gauge reads 12 at idle and 25 at around 2000 rpm. This engine runs around 500 HP from the goodies added by the previous owner. Not sure what he did but I was pleasantly surprised the first time I drove my car. I dynoed it at 411 RWHP before I installed the bigger injectors. My 32 lb injectors were running at 100 duty. Now running 36 lb.
Anyway, it was a lot of work at home in my garage to replace the "O" ring. Is there a chance I should have used the fatter "O" ring? Could I maybe add another couple of qts of oil and slope the car forward to maybe submerge the "O" ring to diagnose the problem? Any advise sure would be appreciated. I'm at my wits end.