the outside of the case makes no difference. In fact you can swap GM rotor packs into Ford cases, you just have to remove the alignment dowels. It's the inside of the case and the shape of the inlet and outlet that makes the generation. You can also swap a GM snout onto a Ford case the same way. We have done it in the past, on custom installations because the Ford snout was too short, that and th fact that it used a pressed on pulley, and at the time there wasn't anything else. Nobody wanted to use the GM superchargers because they were a nightmare to package so we had lots of guys come over asking how to adapt things. You can also swap a M112 snout to a Gen 5 M90. I've been messing with these superchargers since there was only dial up. There is a ton of information I have posted over the years comparing the different superchargers I use the same forum name everywhere.
Jeff
