Hi all, 
I recently purchased an escort and there is a different axle in it.
The diff is a 4.1:1 and it's roughly 8.5"
I would love if someone could help me identify it. I searched the serial number on google and no luck.
Images:
http://img705.imageshack....05/9546/imag0061pn.jpg
http://img593.imageshack....93/8909/imag0060dr.jpg
Both have same 108mm pcd.
I've never seem a diff like this before. Looks like the spider gears are internal.  

Part Number 71ag 4005 aaa 

looks similar to the v6 atlas diff that came with my capri but the rear plate doesnt have that loop for the handbrake on it

I've been looking at a lot of the capri diff's lately but can't seem to find one to suit. I will take the cover off tonight and take a photo. They look very similar!

 
Exactly what Whooligan said ...

Ahh excellent. This is actually off a 1976 2 Door MK2 that I'm eventually going to do up to a rally car. So bad news. Bugger.
Cheers