rate

Im looking to get the upr k member coilover kit, but dont know what spring rate and length to get. Ive searched around alot but cant come up with a straight answer. Car is around 3700lbs, going to be using the stock bilstiens and normal lowering springs on the rear(irs). Mostly street and strip...

So I have a twin turbo hellion kit on my 03 cobra and currently running 10" 350 lbs springs on the front coilovers and Eibach pros in the rear. The car originally had 14" 175 lbs springs in it and it handled like crap. Has been much better with the ones in it now but just curious what you guys...