According to the FSM there are no adjustable steering stops on the MJ, I’ve never looked. You can swap WJ lower control arms for more clearance but need to cut down the bushing,
There are a couple pictures of the retrosound unit installed in a 96 XJ in one of the reviews.
https://www.crutchfield.com/p_068GRANM1B/RetroSound-Grand-Prix-M1B.html?tp=49934