Hey Sike, figured you might ask that question.
Here is the selection of MGT spur gears:
Mod1 spurs
All you have to do is slightly drill out the center hole to fit the traxxas slipper bearing, and drill out 3 of the small holes to fit over the bolt bosses on the slipper hub. It is wise to use small washers on the 3 allen head screws that hold the gear on. I will snap a pic of the gear when I swap the 52t in.
I have given up on 32p for the larger vehicles, mod1 is so much more forgiving than 32p.