Why not just lengthen the lowers a little. Enough to get the correct caster reading. If the uppers are too short then the only other option (aside from relocating them on the RA mount) is to lengthen the lowers.
This is as simple as the installer didn't use Loctite and likely didn't properly torque the bolts.
I have been a gear installer since 1996 and have never had this happen. Literally thousands of setups under my belt. I have repaired the resulting damage from previous installers not using...
Any chance your transmission crossmember is 180* out?
One time way back in the day I did that and the rear shaft was cocked over to the side a few degrees and caused vibes that weren't there prior.
I noticed the witness marks on the crossmember and saw I had re-installed it 180* out.
Count my wife and I in as well.
Undecided which rig we'll bring. Her ZJ, my XJ or maybe I'll put an XJ grille on my Ranger?
1. Andy "LR2" Bagwell
2. Ledford's (043500)with the MJ (as long as pending financial issues resolve)
3. Calvin Ledford with his XJ (my oldest son ***see above)
4...