i just tried to install a GPM alloy motor mount but nothing fits...
-the kyosho ball diff adjustment screw is pressed against the mount
-the toothless half of the stock pinions lines up with the spur gear...
-the \"slide from the side\" motor cover only goes on (forcefully) when there are no space plates in housing
what gives?

GPM stuff links to one another, so for the mount u have to get GPM ball diff,pinion,motor in order to fit.