X-Factor,
I am curious why you chose the 3.75" backspaced RockCrawlers when 4.75" are available? I am running 16X8 ARs with a 4.5" back space on mine with a 3" suspension lift and still had to do some fender trimming to make them stuff. A body lift will alleviate a large portion of it, but the possibility is that had you used a deeper backspace you probably wouldn't have to worry about it as much. In fact, as my truck has proven, you can still get a reasonable size tire on with just a suspension lift. And the worse thing about the whole deal is that by going to all that work fitting high 32s or 33s on your X, you still only have a 1/2" of extra ground clearance at the low point. Is a 1/2" really worth that much work and expense? I would change to a deeper backspace rim, do some fender modifications and call it even.