The rear springs also need to be stiffer and shorter and unless you want a truly "slammed" car with outrageous tire wear you will need thicker spring pads all around. After installation, you will need to adjust the rear control valve link like you would for the stock springs, that is with 1/2" or so free suspension compression before the self-leveling action kicks in. Here's one thread with my observations (see post 6). Happy motoring. Mark

http://www.peachparts.com/shopforum/showthread.php?t=89783