Hi can anybody tell which gear should I by( the one that goes inside the transmission), I have a 1970 fb mustang with 4 speed toplader and 9" 3.5 differentail, please tell me whic is the correct one and where can I buy it.
Thank you very much
Florencio

 

Here is a link that may help you out. It looks like there are a couple different ones that can be used with a 3.5 rear gear. I would imagine it would make a difference on what tire size you are running.
http://www.4speedtoploaders.com/shop...arget=d85.html

Hope that helps. Good luck!

 

According to my mustang restoration guide it calls for an 8 tooth drive gear inside tranny @ the 3.5 gear ratio.