Urban Riot,
If you're talking the '47 2nd series through '55 1st series 4400's
The 4409 (with flatbed) curb weight is: Approx 5,320 lbs
Max Gross Vehicle Weight is: 12,500 lbs
Not sure about the rating nomenclature.
I pulled these out of my Truck Data Book. If someone else can correct me, please do.
John