[lincpimp]

I took a 46t kyosho plastic spur, and had the machinist open up the center hole so that it fit around the diff cup. Then I took the steel spur to the grinder and removed the teeth and a little more. So basically I made a backing plate out of the steel spur. It is hardened so drilling it was not an option. I made 4 slots with a fiber cutting disk, and then drilled 4 holes in the plastic spur. Bolted the spur to the backing plate with nuts and bolts, plastic spur on the diff cup side. Last I made some 1/4" or so plastic spacers to put under the diff bulks to raise the diff enough so that I did not have to enlarge the hole in the chassis.