I know that SN95 Bullitt/Mach 1 spring are suggested for the swap but what about '98 Cobra springs?? I found a set of four locally.
I used a set from a 99 GT. The rears were too soft/short. The fronts were perfect. I put the stock springs back in the rear and I am very happy with the result. I have about 2 inches between the top of the tire and the fender lip all around. It feels much tighter in the front as well.
I also used stock '99 SN-95 Stang springs.Very good handling,lowered about 2 inches all around,stiffer,but not uncomfortable (I want the car to be a good all purpose car).
I've always wondered how you used the rear springs. When I put mine on it was slammed in the rear. It rode like junk. I was afraid of getting pulled over for trafficking withe the trunk slammed to the ground (San Antonio, you know what I mean).
Did you use spacers in the rear? I've seen other cars with GT springs and they had the same problem.