will this work in a e revo?

[offroader]

I'm also doing a Revo BL mod and need some help! Not sure what type of gear to buy I'm going to use a 12L Feigao motor with a BK 9920 esc. What type of gear do I use on the motor 5mm bore 32 pitch pinion gears? or 5mm bore, mod1 pinion? What is the difference and why do they have so many?
What size ( # of tooth) would be best suitable for a Revo? I was planning to use the stock tranny that comes with the Revo or a Emaxx tranny if I can get a hold of one.