The JK will be a 31" or 32" tire depending on platform, to fit a 31" on a WJ we have typically had to use a 2" BB. For a 32" tire you would be looking a ta 2" BB and the trimming the front bumper, maybe pinch seam in the wheel well and not having much flex. Stock 16x7 WJ wheels have a 6" backspacing, while the stock JK 17" rims have 6.25" backspacing. Your wheels will sit slightly closer in to the body, couple this with 32" tires that are wider and stock suspension will result in MAJOR rubbing.