The 3500HD Dually was a company "work" vehicle as is my current 07 F-250, 142" WB, gas 4x4.
I got the Dually as a hand-me-down from someone (I assume) that actually needed the beast due to the nature of their work.
Since I'm a manager in the Engineering Dept, and I seldom carry more than a set of prints and a calculator yet I frequently run the full length of the state. Access to cars-only highways, tunnels & bridges was critical. Hence the extreme under-registering.
And if memory serves me correctly, it was actually registered at 6600 pounds, not the 8600 I mentioned earlier.
In January 2007 I was issued the F-250 pick-up which I'm currently driving and have since put over 100,000 miles on it.
The only thing I ever had to replace were the front Auto/Lock hubs.
While not nearly as comfortable (or fast) as the old Chevy, the Ford has been incredibly economical to run.
No problems ever! Not so much as a rattle, shimmy, or a check-engine light in 100k!
Sorry I'm so long winded here. I guess it's a noob thing.
-Ej-