The Thrasher kits moreless had the exact same spring setup as the current Transgo kits, the original Thrasher kits were made by Transgo fwiw. If you are looking for a considerably firmer shift feel then the Transgo kit wont do what you want, though it will slightly quicken up the shifts. There is more to these transmissions than just shift kits but since there is nothing really easy to get to while in the car the shift kits seem to satisfy most peoples needs. I was thinking for one reason or another that the Thrasher kits changed at some point but cant say for sure. The bonus with the Thrasher or Intense kits are the adjustability of firmness from mild to wild. If added insurance and a slightly quicker shift is all you are looking for then the Transgo kit will work fine, just dont expect more than a minor change in shift feel because they dont provide that.
