ok so an update: i noticed this Sachs clutch for sale on ebay second hand and the seller states its slipping at 420bhp? Same as mine , ive been stripping car looking for slave cylinder leak as there was residue in box - in th end it was rocker gasket - and left it as is but with slip on top end boost, if that makes sense, but having seen this ebay auction obviously my question now is which is the best clutch for 420 bhp?

Thanks!