Slipperntial my way. Maybe.

[Patrick]

I'd say they used idler gears in the e-maxx transmission, because if they didn't then the input shaft would sit about 20mm lower. Good for center of gravity, but the 66t spur gear would be hitting the chassis and probably drive shaft. The motors might also sit too close to the batteries, making them too hard to get in and out.

You could put make a mount for a center diff and put that in the maxx, but the problem is that the motor will probably be sitting so low (this if if you put the motor in the center, above the diff with the pinion going straight onto the spur) that it could hit the chassis. Depending on what chassis you have you might be able to make it work, but could be hard.
Do you want it to have a center diff or constant 4 wheel drive like the maxx transmission.