hi guys,
as far as the ITBs are concerned, as pictured they'll bolt right up to the m42. it also has all the required feeds for the ICV, breathers, brake servo etc.
I can build up throttle bodies like mine for about £400 ($700) without the intake plenum, the plenum i'd have to get a quote to have one built up to the same spec as mine by a local place, would probably cost about £150 at a guess, mb more if carbon fibre. I just don't like messing with fibreglass as its a pita and stinks.
If you want a setup similar to mine but made by a mainstream manufacturer - then dbilas or bmpdesign are the two options. both will cost you a lot more money though (circa $1700 iirc), and i have my reservations about the dbilas design (never seen a BMPdesign one though).
as for max rev limit and the myths surrounding the e30 crank pulley etc, I'm not looking to rev to highly (yet) as its my daily driver and its still on hydraulic lifters etc. for now my rev limit will be as low as stock, and after a few thousand miles, I reckon circa 7,250 or 7,500 rpm will be my limit. As for the tales of the crank pulley breaking up at 7,200rpm or whatever, these claims appear to be totally unfounded. I think what is more likely is that the rubber is perishing in certain conditions with age, our engines are 15yrs old after all. I've inspected the crank pulley going onto the engine and it shows no evidence of wear/perishing. I have never really got the whole get to 7,200 and your crank pulley will disintegrate thing. I know of m42s with this vib damper running up to 7,500 consistently with no ill-effects. It can easily be overcome anyway, but i'm not particularly concerned about this. If someone can give some concrete details of one breaking up etc and pics etc and the conditions under which it broke up, i'd be much more concerned. but tbh i've never actually seen this, just heard tales.
Cheers guys!
tim