yeah it could be an offroad versus onroad thing as far as flex. Ideally maybe zero flex is "best", but, what is easiest to get working setup wise is flex. Sometimes you gotta take from Peter to pay Paul as my grandmother used to say lol.
as for chassis strengthening, it will be interesting on how to do that to eliminate flex. On other cars I have seen guys rig up turnbuckles to the center diff and various tranny cases for stiffness, but in this case the way the center diff is I don't see how you do that.
Tomorrow gonna do some more racing action. I did put a fan on the motor, its a simple integy combo motor heatsink and fan I had laying around that actually fit quite nice. I'll take a pic when I get a chance and probably redo the plug system on it.