Cranking your torsion bars will increase the angle between your upper and lower control arms, and give you increased lift. Tighten the adjusting nut that connects to the adjuster arm to accomplish this. Mine took about 12 turns to get the 2" of lift that I initially had. While this is a great way to get extra lift at no cost, be aware that it will wear your t-bars out prematurely. No big worries though, I did mine about 75,000 miles ago and just last weekend reindexed them to regain my lift. Have fun!!
I'm still trying to wear out my tires, they are my second set, but original 225/70r15 size. I have approximately 4" above the tire in my wheel well though. 31's would be about 3" bigger in diameter, so they'd eat up 1 1/2" of that, so I don't think they would be a problem at all to run.
I've upgraded to 30" tires now. With the old flares, I would not have been able to fit 31's, however, with the larger V6 flares, I could without a problem. They don't stick as far into the wheel well and I gained about 1" of gap in front and behind the front tires.
In the Asia they still make the old body model along with the new one. I have a -06 and it's exactly like an -04 with the torsion bars. They sell them all over Europe as late as -07. Iv'e fitted 32" with a 2" crank and a bit of plastic cutting in the wheelwells. If you cut away some sheet metal behind the tire, you can problably fit 33x12.5's with a 2" lift or even 255/85-16. It's mostly width that causes rubbing. 4X4 (old model) comes stock with 28's - 31's.
I got about 3" of lift up front with my torsion bars.. and i removed mud flaps, and did minor cutting with drimmel and ran 33x12.50's on 15x10 rims for a short while... only rubbed at full turn, which could have been fixed with just a little more time on the drimmel.... They stuck out a solid 3" or more past the fender flares...