300# if you have enough platform threads to hold the car up. You have a very front heavy car, but the short wheel base may over shadow the initial hook up problems that you are about to experience with that scale report. The rear will like the lightest spring you can use to hold the car up to plant the tire better. If you have run this car already and have no issue with hook up, then the lighter spring in the rear may cause you to drive into a wheel stand and would prefer a stiffer rear spring. The front spring rate was chose to help transfer weight to the rear by storing more energy. This is the best I can do with the little info you have provided for us to evaluate. Ladder bar crap likes different rear rates so if you are a 4 linker guy you should be in the pocket or at least real dam close.
Good luck in 09