Actually the original Magnuson kit for these engines used the M62 supercharger. The M90 was used in the Buick 3800 engine. This set up is not at all compatible with the 3400 due to it being a completely different design in engines. Although AleroB888 did take a M90 and fabricate the inlet and outlet flanges required based on the Magnuson kit. On top of that you'd have to get a proper length snout as well as mounting brackets for support. Doing something similar to what he did is a difficult task.
These links would be useful to read. If you can't see the pictures then just create an account on
www.60degreev6.com
http://60degreev6.com/forum/showthre...-first-mock-up
http://60degreev6.com/forum/showthre...roject-Updates