[Build-It-Break-it]

The Panhard bar will move the axle over left to right .

First I would check if the lower trailing arm brackets are welded on your axle according to the speedtech instructions. Then make sure the axles is centered left to right front to back under the car in the wheel wells.Then adjust (lengthen or shorten) the lower trailing accordingly.

Every car is different and without pics it's hard to see what you have it set up to.