The Centerline springs are similar to the old IAP springs. They were designed back in the day when the most popular wheel/tire set was a 205/60x14 or 185/70x14 with soft sidewalls. They work on a racetrack, but I found them to be much too stiff for poor quality roads.
They were replaced with a set of Alfaholics fast road springs which provide a much more comfortable ride while still be significantly stiffer and better handling that the stock setup. You can get the Alfaholics springs in different ride heights.