[Mike Simard]

That rear sway bar rate sounds much too high. On my regular Cobra, I used a Speedway 1" solid bar on a 12" arm which according to their charts is 272 lbs. It didn't necasarily have oversteer but if you were turning on a very uneven surface, you could feel the rear get loose because the sway bar wouldn't allow the suspension enough travel to keep the tire planted. Now I use a 1" .095 wall bar and the car feels just right. The chart shows this new rate to be 155 lbs which is almost half the old rate.
BTW, doesn't the coupe (FTF) have a nice suspension? It's nice the way the moved the control arm pivot points out to use a long control arm. I wonder what the camber gain per inch of travel is.