In my opinion, the 06 trucks are the same and retaining the LLY monicker is one of the stupidest things that GM could do. It just creates confusion. The only real difference is the ECM programming and while the HP rating remained at 310HP, the real world showed it more like 340HP or slightly above 50% of the difference between teh true LLY and the LBZ. When properly tuned they all run the same so no loss.