I've had low oil pressure ever since I started my 408 stroker engine, 20psi at idle and about 40 psi at WOT. When you put a stroker crank in you have to put washers under the windage tray to keep the throws from hitting it. I was told by Erik at HKE to be sure to have about 1/4" gap from the end of the pickup tube to the bottom of the pan. I've never really had good oil pressure so it finally bothered me enough that I pulled pan to check the gap that was there. When assembled, HKE had the 1/4" gap they speficied. I have a 4.8 completely stock on the engine stand so I pulled the pan on it and found that GM builds them with 1/2" gap to the bottom of the pan. My first attempt to fix my oil pressure issue is to change my gap to 1/2" like the 4.8L engine has. I also have purchased a new pickup tube to oil pump clamp that uses both bolt holes in the pump to center up the tube inside the pump bore. BRP Muscle Rods Your LS1 - LSX Conversion Kit Specialist I also noticed when I took the pump tube out that it had the thinner blue o-ring. I have a stock 2004 6L o-ring and its red and a whole lot thicker. I'll be replacing that while I'm in there. Hopefully this fixes the oil issue. What I'm thinking is that with the sump being too close to the floor of the pan the pump was cavitating and pulling lots of air up with the oil.

Wish me luck.