Just installed a Goodwin Performance clutch kit in the wifes 98 Indy 500 and what a differance. I usually install my own spring and helix combo but there was a new kit on ebay last year that I picked up for only $65.00. Thats a new primary spring, weights, secondary spring, helix and shims. The thing that got me was the weights and springs that came with the kit were a hell of alot heavier and stiffer than I thought a little piston port 500 would pull, but let me tell you, it works great. The weights went from 10m5 (49.5 grams) to 10al (53 grams)! The primary spring went from stock gold (100-280 lbs.) to Goodwin black (180-330 lbs.) The secondary went from stock gold (24-49 lbs.) to Goodwin black (48-75 lbs.) The helix looks like maybe a 40-36 or 42-36, I cant tell. But man this sucker pulls real good and from a dead stop, its right there. Kicks in about 4800-5000 rpms. Best $65.00 I spent in a long time. Hope this helps any Indy 500 riders out there. Later.