going along with the 99+ upgraded tranny i know O.S. Giken makes an upgraded (high strength) input shaft, their gears are also supposed to be stronger, of course that is just what I have heard and don't know if it is a fact, I just know their input shaft is upgraded and stronger. Other benefit to the O.S. Giken is its a close gear setup for either 3 or 5 gears which would keep your rpms up higher which is better suited for drag racing.