This is a heads up for the BEC boys on here.
I offered to post this on behalf of a member on the Cobra forum.
He has a 3.14 Sierra diff (7" Push -in shaft type) for sale on ebay ford sierra rear diff | eBay
He is after the same type diff but 3.62 ratio as its more suitable to the engine characteristics of a Rover 3.5 V8.
I'm not suggesting you could necessarily get a straight swap as he is aware of the rarity of the 3.14 but if interested his name is Mick Reed and can be contacted on 01954212931 work hours only.
I must stress I haven't seen the diff personally so cannot vouch for it's condition etc.

Regards,
Andy.

Hi Andy.
I have been watching Micks diff on the Bay , hoping to win it.
Also, did you notice my post earlier selling my 3.62 diff.
I have emailed Mick through EBay to see if we can come to a deal.
Brad.