I’m trying to identify the rear end in my 69 XR7. There is no tag anywhere to be found. I have only a pinion support casting number (C5AW), a Dearborn Foundry marking (DIF), and the attached pic. Door tag and Marti report have the axle as a “6” (3.00 non-locking gears). I suspect it’s original, but would just like to know if there is an easy way to identify it as an 8 or 9 inch diff to satisfy my own curiosity.
As the others have said it’s a 9" by looking at it. But we all have to start somewhere. Take a look at this guide. One of the best for learning this stuff. http://www.kevinstang.com/Ninecase.htm