I have an 06 GTO engine in a classic car. It was one of the few engines that had a pressure relief valve built into the oil pan. When the oil pressure got to around 50psi., it would drop to 25psi and remain there until the pressure dropped below 25psi.. It would then show correct pressure until it got to 50psi again. The cycle then repeated itself. ( I have had the pressure valve removed and plugged, and now it reads correctly throughout the oil pressure range )
I mentioned the above only to find out if this engine held more oil than others. I put in 6.5 quarts of oil (with a new filter) and it reads a quart low on the dip stick. Thinking it might have the wrong dip stick in it, I bought a new dipstick and tube. It is installed correctly and still gives me the same reading. At 7.5 qts it is at the top of the checkered "full" mark on the dipstick. Did some LS2's require more oil than others ? I don't know if one quart too much oil will hurt anything, but I want to put in the correct amount.