I just put a 1974 C-4 in my 66 Mustang. I used the old 66 C-4 gear on the end of the speed cable and the speedometer is running about 20 mph fast. I took out the gear and it has 17 teeth on it. That is a low number of teeth. I think they start at 16 and go up to 23. Does anyone know of a site I can go to that will give me details about how many teeth are on the tail shaft? The only numbers I could find on the tranny is C6AF7D027-B Thanks guys
