Ok, my wife's yukon isn't holding oil pressure any more and I've determined with 2nd, 3rd, and 4th opinions, that it's new motortime. It's unfortunate because it's only got 130k on it and is a super clean truck. It's a 2006 1500 4x4 yukon xl with the L59 vin code Z 5.3. My question is if I can replace the motor directly with an L33? It SEEMS all I'd have to do is swap the injectors and then I'd have an ethanol burning L33 (only on the rare occasion e85's cheap enough to be economically feasible). I'd love to swap in a cam and even if I do or don't do that I will get it tuned...if this works. Anyone have any advice? Thanks for any help.