My MRL 408 is finally running.

My 69 Dart swinger has 300 HP ... and it is far from a scary ride... cannot see going to 400 HP being that much different/scarier ... now if you go from 300 HP to a 500-600 HP engine that i would think differently ...
I would agree that over 500 HP can be a stressful ride in certain circumstances ... I frequently drive 600 Plus vehicles in a curb weight of 3500-4500 lbs and even then i have had times that could of gone wrong ...