Yes, it is a plastic spur, the Ofna 51t. I will have to do some modifications to make the diff fit in. My plan is to move the rear diff holder post thingy towards the rear to fit in the slightly longer MBX diff. Then I will use the shorter MBX dogbone. I don't know for sure if this will work. I'm just hopeful at this point. It may take me awhile but I will post my progress.