[65Kustom500]

How do you tell a 8" from a 9" Im not sure what my car has. I have been told EVERY 289 car had an 8' unless it was a HiPo ... any info?

 

[etcetera]

The 9 inch bulges more at the bottom so that you won't be able to get a socket on the bottom bolt.

 

[psivory]

Not every 289 had a 9", mine had a WER rear end.
Here is a good site for info:
http://www.kevinstang.com/Ninecase.htm

 

[retyler]

The '8inch' is more oval looking at the back of the case, sorta of flat on the top and bottom and some had a fill plug on the back. The '9inch' has a more round case.

 

[ckelly]

Jack the front of the car up a bit so you can look straight at the rear end. If you can see the lower nuts under the pinion, it's and 8". If the pinion casting hides the nuts, it's a 9". The socket idea is also correct - you can only get a 9/16" wrench on the lower housing bolts of the 9".