it is similar to the 8.8, but i guess different, why don't uk people fit the 8.8 like the americas do to the xr4ti, its a sierra, but badged as a murker, with the 8.8 its cheap, strong, hundreds of ratios to choose from, and maybe 20 different LSD's to choose from depending on use and price range, is available in front axle setup as well with normal rotation, or reverse rotation i believe, just seems mad using such an expensive part when a just as good factory ford part is available with more options and cheaper, only guessing the cheaper and options bit, but as its for a cosworth my guess is they think of a number and times by 10 and add a zero to come up with the price.

how the 8.8 is fitted http://www.key-ideas.com/DGKurTwo2-040604-8.8LSD.html

£830ish for complete new 8.8 with 3.55 ratio and LSD, should be good for way more HP than any cosworth can chuck at it.
http://cgi.ebay.com/ebaymotors/NEW-0...Q5fAccessories