Willwood brake kits

[CTE]

For some reckless reason, I am considering purchasing the above type kit for my TVR S1, which has standard Ford Sierra dia 243x24mm (XR4i I think) brakes as standard. The brakes work ok, but the discs are showing signs of surface cracking due to serious trackday abuse (overheating I am told, but they still worked).
The above kit has 283x24mm discs, and comes complete with mounting brakets etc. The wheels are standard 15"x7J et25, and as far as I can tell, the caliper piston is about 50mm dia.
Does anyone have any experience of these kits, ie do they fit and do they work? I am reluctant to fit the much cheaper option of Cosworth Sierra calipers due to unsprung weight, oh, and their sheer weight!

Many thanks

Mark

[GreenV8S]

There's no problem on the diameter and the wheels have lots of room at the back so I don't think you'll have any calliper clearance problems either. Just make sure they clear the wishbone on full lock, this can be a problem if you use an adapter plate that drops them. With those wheels and superlite callipers the limit is around 300mm, which is just barely marginally possible if you're prepared to spend a long time moving stuff around.