Drivetrain Upgrades

[KYLL_E-MAXX]

I was thinking about getting the Mamba Monster Max (if it's as good as it's supposed to be) or a 9l/9920 or something in my E-Maxx. I would be running 14 cells with it.

I was just wondering if the 8 spyder differential is really neccesary. It cost $300 which is a bit pricey. I was also wondering if I can run cvds with my RPM arms. Some people say the arms flex too much. And do I need a new chassis? I just bash and every once in a while I go to a track.

Thanks