I found a rear antiroll bar specifically for the excursion.
By far the best mods though were the V code front springs and the rear air bags. I plumbed them into a 7gallon tank to soften the spring rate of the bags. I got the idea from bruce1954 at tds. I usually run them at 20-30 lbs and it rides great. I pump them up to 50 or so to tow.
With 285's and V codes, my X was at 82" or so. With 315's, I fit in my 84" garage with an inch or so to spare, depending on how pumped up my bags are.
I test drove about 20 X's before I bought mine, and the lifted ones drove the best by far. Getting up off the bumpstops makes all the difference.