yea they dont care... if you run a M90 you better keep the psi down or build the motor cuz the stock internals wont handle the pressure.... low rpm psi.... so you eitehr get alot of low end tq lower hp due to lower psi or you can run a standard
vortech/procharger blower and get higher hp lower tq and higher psi saftly.
or you could go turbo as some have done, you could fab up a lower intake to make the twin screw work... it would be some work, you should find out if it will mount to the supercoupe M90's stock lower cuz that will bolt up to a pre 99 set of heads... but it wotn line up with teh belt drive and other issues but its a start. you might could get KB to make a custom belt drive extention or something to meet it up with the belt. go to
www.v6power.net and talk to v6sprout he has a whole supercoupe motor in his car and can tell you how to go about it.