As title (posted this in the general section then spotted this more appropriate forum, sorry).

Back in the Cosworth world after years away, and I need to change the rear diff on my car, as frankly, it's crap. It's either a totally worn out LSD or the previous owner/clown has fitted an open diff. To be honest for all I know he's fitted a 7", I got the Cossie paranoia already.

I know the differences aren't huge between a 7 and 7.5, but know they do look different externally, but exactly the differences I don't know, and searching has found nothing.

Can anyone explain for me?

Thanks in advance.