The diesel mounts are made of tougher rubber to cope with the extra movement you get from a diesel engine, or in this case a more powerful engine

I'm also going to try and fit a flexi-joint off a mk2, (the name describes it quite well) this goes between the downpipe and the middle box and again deals with the movement of the engine, i dunno about you but i'm always having trouble with that joint as it is, i imagine it'll be magor problems with 40+bhp extra.

You should be able to get the mounts from any good parts store for about £10 each (i use volkspares) as for the flexijoint, hopefully it'll be on the mk2 downpipe i'm going to butcher (can anyone confirm this???) if not i'll probably just get one from the scappies