Thought that they were 9-3/8" ring gear rear ends?
Saw plenty of 9 3/8 rearend/third members in yards over the years. Not sure when Ford changed from the 9" to 9 3/8" and found 9" on 66's and 9 3/8" on 68's.
![Roll Eyes ::)](https://www.concoursmustang.com/forum/Smileys/default/rolleyes.gif)
Also to add possibly to the confusion is that in year 1966 they installed 9" and 9 3/8" during the same production year. Sorry did find info for 67 - later years appear to not have as much published research and info. Found the following inside a 66 discussion a poster made.
"In '66 a two-digit code began to be used, with the second character either a number (non-locking) or letter (locking)."
Lots of guys pulled them in yards only to discover they would not work in the Mustang, Cougar, Torino .... rearends if that is what your looking for. Have the curved upper reinforcement rib in the third member and I think they are all use 31 spline axles.
Checked the MPC from the year and there were no two characters listed. Looking at T Bird sites/forums it appears that two digit/characters is normal for some years though have not found site or post with a decoder ring. At the same time found pictures of door tags with just single characters.
![Huh ???](https://www.concoursmustang.com/forum/Smileys/default/huh.gif)
Here is what the front and the insides of the 3rd member/pumpkin looks like on a 9 3/8" Does it match what you found?
![](https://www.concoursmustang.com/forum/gallery/19/6-280923234208-194611589.jpeg)