Modifications made since the original post:
- I eventually gave up on the brushed setup, and I replaced the all-in-one electronics with a Spektrum receiver and a Turnigy Trackstar ESC (HobbyKing's rebrand of the Toro Brushless Micro ESC). The motor is also Turnigy, a 4300KV brushless motor that's a rebrand of the Toro Brushless Micro motors.
- I also replaced the stiff purple springs that came with the GPM shocks with the softer yellow spare springs. I overestimated how stiff the suspension needed to be, and now the vehicle handles small bumps better.
- Without the all-in-one electronics box to hold the servo, I found a little 9-gram servo bracket on eBay and mounted the servo directly to the chassis.
