The 94mm rear driveshaft we all know but with round hole axle
Optional rear universal shaft. You also need to change to the bigger 13X19X4 bearings in the hub.
Parts needed to run 94mm rear unversal:
MYB0052-01 Rear Universal Driveshaft Pair 94mm
MYB0168 13x19x4mm Ball Bearing
2x MYB0048 Rear Bearing Crush Washer