Ok, so I have a drive-shaft that came off of my 1966 mustang which was a 6cylinder with a C4. I am wondering if the drive-shaft will work after converting my car to a 9" rear-end.
Basically my question is did they use different drive-shafts for different cars back in those days?
Yea, it should stilll fit. I swapped rears in my 77 Comet from an 8 to a 9". Same driveshaft fit both, had to use a different U joint though. Went to the local Advance Auto and dig thru the U joint boxes till I found the one I needed to mate the 6 banger shaft to a 9" yoke.
9" swap and you still want the old driveshaft? I would have a new 3.5" moly tube built with spicer joints. you dont want to find the next weak link the hard way.