If I were to go back I might have done this to my stock 5.3. First thing get the trans all built up. Then 4:10's and a Trutrac. Then cam ls6 intake and maybe lq4 heads. And don't forget the nasty stall with that trans. Still not the cheapest rout but cheaper than a built bottom and safer than nitrous. Rev it to like 6500 maybe 7k and it would be fun to drive.