Just bought my first chevy, been a ford man since i could drive, but with the deals they have i could not pass it up. I bought a 2500HD 2WD crew Cab with duramax/allison. I love this truck! I am looking at 18"x9" rims with 4.5" backspacing. Will these work with cranking the torsion bars? and what is the largest tire i can use? Thanks for any input guys..