8" or 9" how do u tell

[jahen65]

can anyone tell me how to know what kind of rear end i have, it is an open diff that unbolts from the front not the back. it is on a 65 mustang. any feedback will help thanks.

 

[geostang351]

they both unbolt from the front. usually the backsided has a bump in it for the ring gear, the 8" has a smooth backside

 

[gbarber]

This is a pretty good site:
http://www.kevinstang.com/Ninecase.htm

 

[10secgoal]

you can't put a socket on the bottom two bolts with a 9in. An 8in you can.

 

[D.Hearne]

they both unbolt from the front. usually the backsided has a bump in it for the ring gear, the 8" has a smooth backside

And the early 9" rears did as well.

 

[taylor4g63]

If you have to use a wrench to get to 2 of the nuts its a 9".

 

[84convertablegt]

what kind of engine do you have. if it is a c code car, most likely you have a 8 if its original, an 8" 2.79. 9" were rare and only in the higher end models. doesnt mean someone hasnt replaced it, but what other mods are done to the car