As i've said in other posts...
Stock... 255/70-16 ~30x10-16
265/70-16 ~ 31x10.50-16
265/75-16 ~ 32x10.50-16
285/75-16 ~ 33x11.50-16
If you do the calculations, a 265/75-16 is a 31.7x10.4, but 32x11.50's are only measure to 31.6x11.25 actual size (before being put on the vehicle).
So width wise, not much, height 2" (1" lift). It is the fact that these tires are only 10.50" wide that allow you to run them with little or no modifications (and that you would be using them on a 16x7 rim instead of a 15x8 rim with back spacing) If you go much wider, you'll need a lift (body or suspension). most people can't fit a 32x11.50 on a 15x8 rim with only TT/War... Section tried this and had alot of rubbing (without Sport or EB trim too)