That's what a couple of the engine builders have said. The motor itself is the same, but they added a gear indicator sensor which necessitated different cases. Not sure if that would affect the mounting/fitment any.
It might not be an issue. Mine is at Livengood's so I can't look to be sure, but I think the cases are exposed (meaning they aren't behind the frame or anything like that). Meaning different cases shouldn't affect how the motor bolts in to the bike. Since the motors are otherwise identical, and the frames are the same, I don't see why it wouldn't work. But I would get in touch with somebody like Livengood (or another reputable engine guy) to make sure.
Part numbers are different Looks like there is an additional gear indicator above the countershaft sprocket on the micro fiche.
