Hey Larry! On your SS the main problem is the convergence angles of the upper arms in the rear. With stock Squish-O-Matic bushings and the U channel arms it`s not too pronounced because the front end will push bigtime before the rear ever gets ugly. Although it WILL bite you if you`ve got serious horsepower and get it sideways! I good friend put his big block `87 Cutlass into a bridge abutment like that.
It`s aggrivated by low compliance bushings and box section arms with little or no torsional flex. We`ve had good luck with Currie Currectrac arms with their Johnny joints. It`s not the ultimate solution but they work very well within the constraints of the original suspension. As you know (and I know Mark will agree with me here!) a better solution is a 3 link like the one we`ve been testing and running in our G-5 car for 3 years or so now. Of course that kind of thing is a lot more pricey... Mark SC&C