Originally Posted by Derf00
Aftermarket spring rates are usually as stiff or stiffer than the more stiff factory version so it doesn't make any difference. Yes, FRPP is considered aftermarket.
Well, there goes logic.
A heavier car will require stiffer springs to obtain the same levels of performance as a lighter car. That's why convertibles have different spring rates. IT DOES MAKE A DIFFERENCE.
The OP should take a look at H&R springs. They are very high quality and available in different rates and ride heights. I'm running Super Sports on my Mach 1 which may be a little too low for a real daily driver, but H&R makes springs that leave the vehicle at original ride height and others that drop it about 3/4".