This is the body I'm going to put on the stock chassis. It's a close copy of a Toyota FJ40. I'm also thinking I'll 3D print some bodies for these cars in the future.
The stock cars use 180 brushed motors, but performance at low rpm is apparently not great. Running a brushless motor is preferable.
I've ordered a super cheap open-source ESC from China, called an AM32, and a cheap brushless motor to try out. All in about £24!
The stock ESC is built in to the Traxxas ECM, which also contains the receiver. I don't want to use the Traxxas radio gear so I'm looking to see if I can find a cheap little brushed esc so I can check all that out.
The standard battery is a 750mah 7.4V lipo. The best performance using a brushless motor is to gear down and use 3S, 11.1V lipo instead. I'm not sure how room there will be under the body of the stock chassis currently so I'm waiting for that to arrive so I can measure up and find a battery to fit.
It's a stock transmission and plastic gears, but I've already replaced the sintered bushings with ball-race bearings. I have some metal gears ordered too which are a different ratio and will be better for slow rock crawling than these stock gears.