Forgive me if this is a repeat, but I did try to search here first: I found this website for decoding the axle model code. I don’t know if it tells me anymore than I already knew other than the 28 spline, but there’s a host of other categories on the site as well:
https://www.fordification.com/tech/rearends_ford06.htm
I’m not so sure it is the most accurate, Mustang and Cougar in my experience would use the same tag code in the same year Why use a different code when the only difference is the springs and mounting hardware. A WES-AG/AJ/AN axle is the same in both Cougar and Mustang in the year it was used. But this shows them in more years in a Mustang then in a Cougar. What I have seen is each year has a set of codes for each gear ratio and they are the same between Mustangs and Cougars.
I do admit I have more experience with Cougars then Mustangs. I also use older publications for interchange and reference information.
One will also find the Factory Shop Manuals will cover axle codes and applications well.
Oh well; so much for an exciting find. Thanks for the head’s up. Just exposes my limited experience. All I really needed to know was it is a 3.00 open rear.
Retro1, if your door data label has a 6 for the axle code, it’s an open rear axle & if it has a letter “O” , then it’s has a locking rear axle.
Can’t read the data label, someone wasn’t very careful with it. When my Marti report comes I’ll have the data from the label; but I did catch the ID tag on the diff: 3. 00 9. Thanks!
Got my Marti today; it is a “6”. Not that there was any doubt.