Found this site after buying my new 2006 GMC 2500HD 4x4 crew. Love the truck , just wish I had some of the info on the site prior to buying it. I was told the truck had the 360 HP engine, come to find out after reading from this site it is the LLY and not the LBZ. Not sure how I am going to handle it with the dealer. Still doesn't change that I have a great truck.