I got 5" of lift, 2" spacers, 3" body. Will I have issues with 31's when turning up front. Or should I cut the plastic bhind the front wheel just to be sure. And by the to give you an idea of how aggressive of tread it will be they're either gonna be the Dunlop Mud Rovers, or the General Grabber AT2's haven't decided yet.

I would put the tires on first, then get with the cutting.  It's always harder to put the body back together then it is to cut it off.