I wouldn't touch an inverted T. Let me explain what happens with this type of setup on an XJ with a lot of lift.
First off, the basic difference between the "T" and "Y" styles of steering concern how the draglink and tierod connect. In your stock system, which is a "Y", the draglink runs from pitman arm directly to steering knuckle, and the tierod connects from the draglink to the driver's side knuckle. You get very positive (low slop) steering from this setup because the draglink is connected directly to the steering knuckle, and so when you turn the steering wheel you turn the knuckle, each and every time.
Even at tall lifts (steep draglink angles), this basic function holds true. The problem with the "Y" is that as lift increases, the tierod is pulled off of a horizontal plane, and as the suspension flexes, the wheels are pushed out and pulled in, which can lead to death wobble problems (nothing additional dampening can't fix). This is why Currie designed a Y system to correct the tierod angle at taller lifts, as well as adding much needed beef.
In the "T" system, the tierod runs from knuckle to knuckle, so you can never get the issue of the wheels pushing out and pulling in with suspension compression. However, the draglink now runs from pitman arm to tierod. With very little lift, i.e., very little draglink angle, this is ok. The issues start when you lift.
The "T" system by nature increases the angle of the draglink because the mount point is moved inwards from the knuckle. The system operates under the assumption that draglink forces will be applied horizontally to the tierod, which happens when the draglink is nearly horizontal. Look under a stock YJ and see how little angle the draglink has. Your XJ is going to have far more draglink angle.
Now, with a lot of lift and corresponding draglink angle, when you turn the steering wheel, the draglink applies force to the tierod on this high angle, and what you get is rotational force before you get side to side motion.
In other words, a steep angle draglink in a "T" system will push *down* on the tierod, causing it to rotate through the motion of the tierod ends, before it turns the knuckle. The result is a nasty dead spot in the center of the steering and ugly bumpsteer, as well as a short life for the tierod ends.
Remember that a YJ setup uses tierod ends and the draglink mounts out in front of the tierod with the TRE bolting back through the tierod. Goatman set up his "T" with a bracket on top of the tierod so forces aren't being applied rotationally. His may work, but a YJ link won't, as they really aren't the same design.
All of this is why most of us favor the crossover. By completely disconnecting the draglink and tierod and bolting each of them individually to the steering knuckle(s), you get the advantages of both the Y & T, but none of the disadvantages.
If you need to get your Jeep back on the road, put on a Moog ZJ steering replacement and keep the Y. You can do the T, but you will hate it and it will be the worst steering you've ever had, unless your XJ is very near to stock. Remember that Rusty's conversion is a T (which I ran for awhile, and which nearly killed me on the highway a number of times).
Nay