I installed most of one on my Dart. My Dart is currently at Hotchkis getting quite a bit of work done to it; however, almost everyone I know who's installed one has loved it. There are some A-bodies that are doing well autocrossing with TVS's.
The kit is missing the 2 parts that make the most difference, torsion bars and shocks. If your suspension is in good condition buy some bigger bars ( 1" or larger ) and some Bilstein/QA1/Fox or Viking. You will still need the shocks and bars with the TVS so you may as well try them first.