My '04 LLY is totally stock for now. Next month, I will be installing larger tires(32-33's). I also plan on buying the predator. Should I buy the predator first and run it for a few thousand miles before installing larger tires, or can I load the predator right after larger tires are installed? Thanks for the help,Troy.

Doesn't make a difference. Load/install them, when you get them. With that said ,your speedo will be off with the big tires until you fix it with the Predator.