im going to shoot for to wide on that, last gmt900 truck i did with 9 wide on wheels and bigger than 11" wide tires, had to be trimed, and that was a 4.8 4wd truck. I try to stay with no more than 11" wide of a tire, then you got to watch your style of tire as well....no M/Ts or crazy lug patterns there not measured with the size of the tire. Or if you do they have to be realy skinny like 10" wide.
just good to keep in mind.