and honestly they looked identical except for the red(na) on being slightly larger in diameter. looking into the transmission it really doesnt matter the radius of the gear because it rests on something like a screw type of device. and with such a small incriment from the gear to the end of the speed sensor the hole lines up perfect... although i could be completely wrong and just didnt pay enough attention. also to make a tt tranny work in an NA you need to shave the starter location down 3/32 of an inch. works great. if you need a tt speed sensor i got it lying around