Lots of great information!
3665RE - I am surprised Ford would upgrade a 250 to a 350 and give you a new GVWR, but I will certainly check into this.
Taken - thanks for the valuable, real world experience.
Jimnlin - thanks for the info on the airbags. It makes sense especially considering the BC unsafe vehicle criteria.
Randy - your story is truly tragic. I really appreciate the spirit of your post.
I humbly offer the following thoughts in the same spirit.
If you hit a stopped vehicle and people die you are almost certainly going to be found at fault, and you will be sued. Regardless of the weight of your vehicle. If you are 20% underweight you will still be sued and you will still likely lose.
The objective, of course, is to avoid the accident altogether and given the physics, speed is far more important than weight -- all else being equal.
Reaching way back to college physics (and verifying it with a google search) I recall the equation for kinetic energy:
kinetic energy = 1/2mv2
This means that 1/2 the mass is multiplied by the square of the speed. In other words -- doubling the weight doubles the stopping distance, however doubling the speed quadruples the stopping distance, all else being equal.
Given this it seems that maintaining a safe speed would be the most important thing to do. Even a truck and trailer loaded to 90% capacity, when driven at too high a speed for the conditions, can be unsafe. While one 10% over the GVWR can be driven safely at a lower speed, i.e., it can have a shorter stopping distance.
Thanks again for the kind spirit of your post and please feel free to share your .02. I need to learn as much as I can from those more knowledgeable and experienced.