What is your motor/power adder combo? If you have less weight on the front end (like a 8.2" deck n/a/nitrous motor) then you may want to switch to a lighter spring rate..125-150. A heavier combo..like a blown 9.5" deck motor will need a stiffer spring..like a 175-200. I started out using the 175# springs that cam with my coilover kit on my coupe...60's were off and the car wouldn't even pull the left front tire on launch. Swapped to a set of 120#...60's came back and much more consistant....yanked the tires hard again.