OK guys, I'm needing some help. I running the RC8 w/ RC-M motor mount.

I am going to be running the Neu 1512 2.5D motor rated at 2050 KV or the Castle/Neu 1515 motor rated at 2200 KV on 4C lipo and a MMM.

What I need to know is what pinion/spur combo can I or should I run?

I keep hearing about the Kyosho 46 tooth plastic spur, will this be a direct fit on the RC8 diff? Also, what range of pinions should I be looking at? I've seen 12 to 15 tooth mentioned, will those cover the average sized track and will the 12 tooth work w/ the 46 tooth Kyosho?

Thanks guys!