When you just adjust the lower arms the axle rotates and when you lengthened them it pulled the top of the differential towards the center of the jeep. You need to shorten both uppers and lowers to actually move the axle back, the angle will stay the same and you will keep your caster. Since the axle moves and the sway bar is fixed to the frame, moving the axle back will give you the extra clearance you are looking for. You could also install adjustable upper ball joints (to gain caster) and pull the axle back with just lowers. You would also have better driveling angles, less coil bowing and track bar brackets that actually lined up with each other.

 

It's all just paper clips and hand grenades. LOL!

 

I had the same problem, do you have adjustable control arms??