Hang on OP, you need to understand whats going on in the turns.
Go find 4 friends. A couple of them robust, and a couple of them with strong backs. Now go find a heavy duty anchor point like a brick building and snuggle up to it about 3 ft away. Bring a flash light. and something to lie down on. Now get the robust buddies to sit on the back corner, and the strong ones to jack the car over until the fender hits the tire in question, by wedging themselves between the car and the building. Now, you will be laying under the car with the flashlight, watching what is going on.
You will see that the body is restrained by the rubber bushings in the front eye and by the flexi-shackle at the rear,and by nothing else, Watch your shackle, as the boys alternately apply and release wedge. Get one of the robust helpers to jump off and then retest.
Now go home and replace all the rubber bits with straight Poly.
Then retest.
Do not use any shackle that uses loose thru bolts, unless it is a welded assembly.
Loose axle U-bolts will allow some jacking, so torque them up.
The closer to flat your rear spring is, the less torque it can apply to the bushings and shackle, and the less side-shift you will have. The more tire pressure you run, the quicker the body will side-shift. Sometime reducing the tire pressure helps. but do not reduce so far as to induce other phenomena like rear-steer in the turns, or premature wear out.
If you have an 8.75, and if you have a more generous clearance on the passenger side, I have found that swapping the right-side axle with the adjuster on it, over to the driver's side will sometimes get me what I need. If there is room in the adjuster, I have on one occasion, ground some spline off the end of the axle.
An anti-sway bar is to reduce body roll. It will do as good as nothing for side-shift.
