John,
Here's a link to a post I put on my web site a while back dealing with the different Jag rears:
http://www.firstcoastcobraclub.com/v...167&hilit=jag*
It will most likely give you more information than you ever wanted to know about identifying them
Alas, CWI has closed.
If you do get a Jag rear, you will be making a little bit of a choice, as all kit cars don't use the Jag rear. For example, the Factory Five uses a Ford 8.8 for its IRS. The ERA, Unique, Power Performance and a number of others do use the Jag.
Have fun with it, and most of all, build it
your way!
Tom