While you comment is true.....sometimes it is better to allow SOME flex (usually torsional) to help keep everything planted. My current race car (non-Mopar) is stiff enough it tends to lift the front tire during the hairpins (not that I am using it anyway). Using common engineering sense (if there is such a thing), if you have a fixed plane (or 4 wheels in this case) and you lift one corner, another corner (or two) will also lift.
Many years ago we had better results on the asphalt ovals with a car that would twist than was overly stiff. We could get the power down much quicker off the corners than the others. I'm just saying there is a fine line to all of this, if you want stiff, fill the frame rail connectors with Viagra! :cheers: