Differential question.

[69Rcode_Mach1]

How do you identify your cars differential to see if its a ford 9 inch or not??

 

[Fomocohipo]

The 8 is oval shaped and the 9 is more round.
http://www.mustangsplus.com/tech/axles/index.htm

 

[PoliceInterceptor]

Here is another one.

Note that the ends of the axel are not a 100% fool proof way to identify 31 spline axels.

http://www.kevinstang.com/Ninecase.htm

 

[69Rcode_Mach1]

Hey guys thanks alot youve been a big help i have the 9 inch.

 

[Max Power]

Also, the bottom two bolts on the carrier for the 8 inch can be accessed striaght on with a socket, but the 9 inch ytou need to use a wrench, cause the carrier (pinion) sits lower.

 

[chepsk8]

Does your rear still have the tag on it? If so, it will give you the gears, and posi or not.

If your "R" is a Drag-Pak, does it still have the "N" case? (only 3.91, 4.10, or 4.30 gears)