how do i know what spring rates to choose?? the car weighs 2400 lbs... without driver i have a 97 del sol with koni yellows and want to go with cround control coilovers... my other mods are energy suspension hyperflex bushings, passwordjdm front 3 point shock tower bar, blox front and rear upper control arms, blox rear lca's, dc sports rear one piece shock tower bar... something that will be good for heavy auto x use.... i was told that between 350-500 lbs would be good. also my car has a bit of oversteer so getting a higher spring rate in the back would help with that right?? Thanks in advance!!!!