Hello! What kind of tires are you using? The spring rates depends a lot of what kind of tyres you are using. I have some experience of coilovers as ii,ve had Bilsteins for the last ten years. If you don,t use slicks i would recommend a springrate of around 450-500 lbs/inch at the front, and about the same at the rear. The damping rate i would recommend is around 325/150at the front, and on the rear i say about 300/100. This is with factory diffs and weight distribution. Just a recommendation from my own track experience. Good luck!