Based on other measurements on the frame - and not just the tire camber - are you sure the frame is out of square? Could it be that the lower arm mounts are too far in?
In any cas, as said a bove an adjustable arm would be a nice upgrade, and will make alignment a breeze to do. FFR uses arms from Specialty Products Company. The street version has rubber bushings like yours. The racing version is probably easier to fit where youy want it to.
http://www.spcperformance.com/images...09_PerfCat.pdf