Those rims would fit, get the non-gm ones if you do. The 4.5 backspacing will not stick out like most will say. For reference look at my gallery I have 4.5 backspacing pro-comps. Or reference nfpgasmask's gallery for AR's with 4.5 backspacing as well. But remember he does NOT have 285 tires on. If I remember correctly he has 245's. I have 265's

To mess around your self with tire size combos. Go to http://www.discounttire.com/dtcs/infoTireMath.dos.

285-55/18 would fit without a lift, with little cladding trimming in the front. (not noticible)


I put smaller rims on after my lift so I could get more rubber. Less rim = more room for rubber and sidewall.

For instance overall diameter of tire before the lift was
265-50/20 = 30.5
after
265-75/16 = 31.7

My current set up did not need a lift to fit the tires in the back but with the 4.5 backspacing the front tires when turned at full extension would rub the back of the front wheel well midly. This can be altered with a little pounding of metal to fit with out a lift though.

Hope that helps.