Check out these links:
Lots of interesting reading. It'* mainly relating to hondas but still cool none the less.
This guy (Larry Widmer) also increases the efficiency of the m62.
"Endyn takes an Eaton M-62 supercharger, rips out the guts and replaces and reworks everything with an eye to increasing flow and reducing the temperature of the intake charge. Carbon fiber rotors (80 percent lighter than the stock pieces) are installed with zero clearance between the rotor and case. The exit side is smoothed and aluminum half-rounds are welded in place to increase the flow. The mods result in an increase from the stock 12 psi to an incredible 27 psi!"
Says they do some
modifications as a service at the bottom of this page: