4 Speed Toploader Swap Speedo Question

[bobmarlojill]

I am almost complete on my 4 speed swap. the last thing to do is find the correct gear for the speedometer cable. I had no idea there would be so many different ones! Can someone help me make sure I get the correct one for my tranny. here are the casting numbers off the tail shaft housing. C90R-7A040-A. I have seen there are clockwise and counterclockwise? different number of teeth? I have this tranny in my 73 with the stock speedo and 17" wheels.

 

[mjlan]

When I had to go through this I called David Kee and he helped me out.

I think you will need to tell him how many teeth you have on the driven gear (gear on the trans. output shaft)and the rear tire OD in order to get a good recommendation...

 

[c9zx]

Go to NPD online catalog, page 170. It gives a fair explanation of how to calculate the gear teeth and left or right pitch. Chuck

 

[Don C]

This should give you some help:

http://www.7173mustangs.com/thread-speedometer-gears?pid=163384#pid163384