Finally getting an early A-Body
I installed a spring relocation kit on my '62 Valiant in order to use 8" X 15" wheels. Initially, it did make the handling worse. The car tended to understeer, as usual, but then would break into oversteer quite suddenly if you pushed it too hard, and had trouble settling back down flat after a turn. Plus, the steering was twitchy. This was with the heavy-duty rear leaf springs and a front sway bar. I believe the engineers would say that the spring relocation kit increases the rear roll center, which you don't want. I found that installing a large rear anti-sway bar solved the problem. I had to have the sway bar made because nothing seemed to be available from the sway bar companies.