how dangerous?
I broke a beefy th350 before and it broke the case & tailshaft. That dropped the front of the driveshaft into the road. The spinning driveshaft beat the hell out of the floor & crushed the exhaust. This was only at about 40mph. 100+ could result in car turn over. Driveshaft loop is a must.
But i would say that if you did a 200 shot off the line, first thing that would break would be a u-joint or twist/break the driveshaft (if its aluminum) and anything else would prolly break right at the line aswell.

