those are the adapters I talked about
:
http://www.rc-monster.com/proddetail...ffshaft&cat=40
But as I said, they are included in the hybrid bulkhead kit so you don't need an extra set of them.
As for the diffs, you need 2 output cups. Those cups are for the centershaft dogbones.
The adapters are for the drive shafts which go to the wheels.