Some parts for sale
 

Hi, got some parts for sale...
Complete back end off a xr4i, diff, shafts, hubs and drums £40.00
MT75 gearbox with lever £50.00.
Best to collect heavy.
Thought I would offer before fleabay.

Might help to put a couple of little bits of info on there mate like where your from and if you know it the diff ratio and condition etc.

Look in location..
Condition of good considering it has been under car for probably 20 years.
Gearbox good what I know.

Bit cheap if from an XR4i as that will be a limited slip diff and they fetch strong money.

Didnt think xr4's had drums on the back ?

Twin Turbo will be the one to tell.

Also I saw west midlands in your location, thats kinda a large area its like saying "South" or "London".

Slippy diff is easy to indentify, turn one shaft and the other side goes same way, normal diff will have the opposite shaft turning the other way...;)

I dont think it is a slip diff, I brought it from an Ford breakers, they said it was from an early xr4i.
Alot of ford limit slip diffs are oil packed and after 20 old years will probably need rebuilding and will work just as a normal diff.