Which Pinion do I need ?
 

I see a few different pinions for 5mm shaft...which one do I need for my gorillamax revo? I have a MGM 160 and Neu1515/1y (2200Kv) with 4s lipo so how many teeth do I start with? (using stock revo diffs) Should I buy a range of 3 or 4 pinions?

We'd need to know what spur gear you're running also.

I have a 65 and a 72 spur.... got both was not sure which I would need ...this is my first real powerful brushless system...hey also do you need to use metal spurs to survive the power or can you use plastic also?..

Use plastic only when possible. However, you really should look into a Strobe spur for that beast.

I wonder if gorillamaxx will incorporate the new e-maxx revo style tranny in place of the older style they are using now then the strobe may not be be needed.