Ok. Here we go...
Assuming the axle shifts to drivers side, which I think it does, and you measure with the point of the triangle going left towards passenger's side...
You know, or can find out, the vertical distance from frame side mount to axle side mount. Call this distance "A". The length of the track bar is "C" and the horizontal distance from frame side mount to axle mount is "B".
The frame side mount, the axle mount & that vertical difference make a triangle. Pythagorean Theorem works pretty well and it tells us that A squared plus B squared equals C squared, or a2+b2=C2
So, what I'm thinking is this: Measure A, B & C.
Measure how far your axle needs to be moved over. You could pick a common bolt on either side & hang a plumb bob from it, then measure distance from disc rotor to bob on each side. Lets say you need to move it over 3/4".
Add 3/4" to "B", use "A" as it is (because ride height hasn't changed) and re-calculate what "C" must be. This is your new eye-to-eye track bar length - so bend everything to clear, give yourself as much adjustment as you can going both ways and call it a day.
I just figured this out in my head while eating dinner... somebody let me know if I need to go back to high school.