My brother and I were talking about my 66 he said it had a C3 auto and I checked the plate and the tranny code is a 6, wich is a C4. I plan on putting a 302 in it instead of the 200. I looked in my resto book and they do not list a C3. Did it ever exist? The motor was replaced with a 200 out of a Maverick many years ago by the PO. I was figuring that it should have a C4 in it unless PO changed it with motor. Any way to tell for sure? First resto, any help would be great!

 

I have heard of a C5, but I have not heard of a C3..

 

http://en.wikipedia.org/wiki/Ford_C3_transmission

there you go, it exists. Im pretty dang sure that you dont want it in your mustang tho if it was used in the pinto!