That is similar to the airplane motor I used. I posted a link to it for $13 in my mudder thread I think?!? Mine was a single motor with gear, and it fit very easily. I just needed to mount a RS gear to the shaft, cut the excess shaft length, and cut a tiny bit out of the orange gear cover. Then a bit of hobby epoxy held it in place. That was the meanest motor I EVER used.
The truck is in parts right now, so no video, but I'm using it to build a new crawler. Once I get the rest of the parts together and time to build it...
here's a pic of it transplanted onto to the new xmod for a test run before I start my project. It even goes crazy on a stock truck!!! Mad tourque through the roof...