Sounds exactly the kind of challenge I would like
Basically you need a wider ally chassis as per the V4 at the worlds...
However after a bit of a rethink.....Is there any point changing to the configuration I've suggested - which is basically moving the weight back to gain more rear traction? I already own a 210 which has loads of rear traction.
Isn't the point of a 2WD converted 4WD car to create a car suited to high traction conditions which basically means you don't need as much rear traction anyway? Might be best to leave it as is - at least to start with anyway.