Here's what the monster had to say....
I have only done limited running so far - had to keep it looking nice for the RCX show. Let me answer some questions that popped up:

is the rear of the motor supported - no it is not. The motor mount is just under 8mm thick(.3") and mounted to a 9.5mm (.375")lower plate on the chassis. the top of the motor mount is also attached on both sides to act as a chassis brace - supporting the rear of the motor simply isn't necessary. The mount is already supported on 3 sides.

Performance? - Using 8s 6000mah packs, it is quite nice. The HV180 controller works surprisingly well and is quite smooth. Quick stabs at the throttle yield quick wheelspin and sideways motion - until the tires get warm. Then it rips the front wheels off the ground. The speed with 8s and the 16t pinion calculates to low-mid 50mph range and should yield 10-20 minutes of runtime(depending on how and where you drive it). With rear only brakes, it is borderline too fast just like this. The installed setup will accept 10s lipo no sweat(limited to 42 volts by the BEC installed, though the esc can accept up to 12s). With the same setup, 10s calculates to 65+mph. This is retarded with rear only brakes. Even the existing setup will "smoke' the brakes after a few hard stops(I know, I thought i cooked the ESC, but it was the brakes that were actually smoking!).
The motor mount will accept a pretty good range of pinions, so with a healthy 12s(different BEC) pack, a giant set of gonads, and some serious space, the truck could probably make 100 mph. The truck itself (and balls of the user) will be the limit, Along with the available real estate.
I also intend to offer different/replaceable motor mount plates to accomodate other motors. The rest of the kit can remain unchanged. I am working on pinions as well. the 16t is the only one i have at the moment, aside from some molded delrin gears(that i will of course try as well). Everything you see is "bolt on" - no modifications to the chassis at all. It took some time to get it all neat and clean like you see it, but it is worth it IMO.

IMO, the car is damn near perfect with the existing setup. Sure, i will try 10s for the sake of science(and different gearing), but it responds, reacts and drives like a 1/10 2wd buggy running a mod motor in its current form - Big thanks to Masterblaster for sending this project my way. I traded my baja away years ago, but this project makes me want to get another one - it is simply awesome!