I have a 96 GT with a t-45 trans and want to go with 3.90 or a 4.10 gears. I just want to know what speedo gear do I need to get to make my speedo correct? Or can I just buy a SCT Tuner and change with it? I was thinking about buying one anyway. Thanks.
You cant correct it with the tuner, and I believe you want the white one with the 4.10 gears...not 100 % sure though. Also be aware, your speedo will still not be perfectly correct and you might as well buy a speed-cal from Dallas Mustang to get it to be more exact. ($100)
www.latemodelrestoration.com sells speedo gears. I dont know if they apply to your gears but you can give it a shot. I heard 3.73's take the purple gear and thats the right one.
If I get the speed cal I wont need to change the speedo gear in the transmission Will I? Just tell the people at dallas mustang what my setup is.
MY 96 Cobra T45 with 4.10's takes a white 23 tooth. I have to replace them every two years (5-7K) year because they get chewed up due to thin teeth.