going to re-use the steelies?
If so, then yea, a 285/70 (~32x11") is about as wide as you want to go on the stock rims as they are narrow pizza cutters. if you want a little more height, go for the 285/75r16s (~33x11")
With my god-awful backspaced rims, i was running 305/70r16s (33x12") back in the day, and they would rub a bit. but again that was more because of the rim than anything.
On the stock rim (or stock offset/backspace) you can get away with 33" tires no problem, some guys fit 35s without rubbing.