| do you have the classic body style or the new GMT900 body style?
if it is the classic i would stay with a 8.5-9.5" wide wheel with a 4.5"Back Spacing,thats what i run when i ran 20's along with a set of LT275-65R20 come in 10PR rated tires or switch to a LT33-12.50R20 or the LT305-55R20 but if you have the 33's you will need to turn the Torsion Bars up plus do some trimming..
__________________ James 
TyreBoyz Pulling Team
Pulling Truck called Late Nights
Puller/DD=04 LLY Reg Cab 2500HD,EFILive'd,Built Tranny and a fe fuel upgrades!
Business Truck
06 LBZ 2500 CC SB SRW,EFILive'd and a Built Tranny
DD/Beat Around
03 5.3L 1500 EC SB,Hypertech,Upgraded Tranny,Exhaust and CAI
Economy Saver
02 VW Jetta TDI,Stock for now but looking at a Chip,Nozzles and CAI!
tricycles = teaching childern from a early age that front wheel drive sucks  |