Steel Idlers (GET THEM FROM MIKE - I made the mistake of backordering from UE)
Umm, stock diffs should work but they wont be 100% reliable, grab a Hardcore Aluminum Diff case (or any aluminum diff case, but the Hardcore ones are very high quality and they have very good tolerances). Also go order
this with the robinson ring and pinion. You can just do the diff mods for the rear, from should be fine, but if you can spring for the front, might as well do it too.
Go ahead and also get the Fastlane aluminum diff case. On
this page the have just the 1/2 case you need for the single speed setup, this way, your tranny will be 100% bullet proof, and if you do thie diffs, so will they.
All the G-Maxx stuff pretty much bolts on.
Start with the Novak Recommended gearing and watch the temps, if its a bit hot, go down a tooth until it runs nicely, if it runs cool, you can try gearing up a bit.