take your time with the shimming of the diffs, or if you can get them, get the upgraded steel diffs, they dont have to be shimmed as tight.
I have been running on a few different size tracks and have found the Kawahara diffs to work at all of them with my JP motor, so you may want to get the 37T diffs. [/B][/QUOTE]
I have gone for the 39 t rings with front one way and 45,46t
and 50,51t spurs with 20,21.22t and 25,26,27t pinions,
So I have a few options there.