If you take the old trac bar from the rear and cut off the bushings from the ends, you will notice the bar is hollow with very thick wall steel (about 1/4-5/16"). Buy a pair of weld in threaded bungs from Speedway Motors (MORE also has them). I had to turn down the insertable end of the bung till it fit in the trac bar tube. Insert the bung and tie rod end on the short side of the trac bar and fit the bar in your jeep. This way you can determine how much to trim off the long end which will go under the spring. Mine was trimmed about 5". Insert the other bung, weld them both and assemble the other tie rod end with lock nuts. Install in jeep and torque. With stock springs you should have enough clearance to prevent rubbing. With 2" springs, it will rub just a touch under max articulation.
As far as 35" tires on 4.56 gears goes, I have plenty of power still More than I had in stock form but I had 3.07 gears when it was stock. I ran 33" BFG's tires until just recently and actually liked that combo better than 35". But I love the clearance and traction of these new tires. I don't think I'd go with 4.88's unless I changed my front axle also. A D30 is marginal with the setup I have. Putting more of a load is asking for broken parts.
If you want some pics of the bar send me an email and I'll email some to you.
'91 YJ, 4.0L 5sp, Atlas II, RE SOA + 2"BDS, 35" Explorer Xterrains, ARB's & 4.56 gears, WARN 9000i