Jeff, the speed sensor is actually on the lsd. Im pretty sure it has nothing to do with the abs side of the car. Its a simple two wire setup that can be calibrated using a digital converter box. The 6spd tranny I beleive isnt suggested because of the gearing for everyday driving and the assumption that it is weaker compared to the other SR trannies. I think that factor comes into place above the 300whp mark. The 6th gear only would come into place if your racing at 120+mph I believe, other than that, in drag racing(1/4 mile) at least, the race's are won in 4th gear, MAYBE 3rd. IF someone was to go the S15 route and were thinking about making serious power and were worried about the strength of the tranny, OS Giken would solve all....$$$$$ Though.