I bet there's not much life left in the springs on your 98. You'll probably find they're rusted and close to breaking as most SVT's that old that I have seen have at least one snapped spring.
If you don't want a lot of drop I would suggest the BAT springs, but seeing as I DO like a little drop H&R's are #1 for me when it comes to conventional springs for these cars.
Either way I would not suggest you reuse the old springs, AND the GR-2's are junk and not meant for uprated springs, they'll blow out in no time. They did on my buddies car!