I was planning to run both of them (one on either side) of the Vanagon's engine, but then I found the Lysholm Supercharger that I now use for a price I could not refuse.
These things are good around 9.5 to 12psi (I really would not run it more then that), and being roots blowers, are great for instant boost.
I'll sell them separately, one has a bent up pulley, so I'd let it go for $250 +S&H or some decent trade.
Shoot me an offer on the other one (the ported one).
Have some compressor maps:
Flow:http://www.rbracing-rsr.com/turbo/TurboMaps/M90flow.gif
Delta T: http://www.rbracing-rsr.com/turbo/TurboMaps/M90deltaT.gif
Power Consumption:http://www.rbracing-rsr.com/turbo/TurboMaps/M90power.gif