JKS track bar question

I currently have a JKS track bar on my 92 XJ and it is the 1" to 3.5" model. I will be adding ACOS to my 3" OME springs to go to around 4" of lift or 4.5" depending how it matches up with the rear height. What is the difference between the 1"-3.5" track bar and the next step up track bar, the over 4.5"?
Can I modify my existing track bar to work? If so how?

Thanks, Tony.

I don't have an official answer from JKS, just my observation from being in the same situation.
The angle of the trackbar at the frame mount will be incorrect. The tube containing the Johnny Joint is welded at a certain angle depending on the lift. A neutral position to allow equal up and down movement would be best. If you go too much higher in lift the Johnny Joint movement is nearly maxed out. I'll guess the stresses on that bolt could be enough to break it, if you're maxing out the joint.
You could cut the frame end off the trackbar and align it to a more neutral position for your lift. You'd want to be comfortable with your welding skills though, trackbar failure could get really ugly.
Also, the 'short' trackbar might not be long enough for higher lifts.

I went from 3" to 6", and had the 'short' JKS trackbar on hand to fiddle around with.

-Ron