A 6400 has a GVW of 16,000 lbs. with a factory flatbed. Add a steel bed or a hoist and you put another 2-3000 on the empty weight. That leaves you with 10,000 to 7,000 usable load.
Any trailer would have it's own brakes so stopping is not an issue. With 6-9000 truck weight, it will take a lot for the tail to wag the dog.
The '48 2 ton had a 235 with dual W-1's (properly sized) and dual exhaust so it could breath easier, and a 700R4 trans. That has a substantial overdrive. 8.25R20 tires and front disc brakes.
I did all the road testing with a farm tractor loaded on the bed, about 1-1/2 tons.
If you are licensed to or experienced in driving big trucks you allow stopping room, don't make quick lane changes or take off ramps like a pickup. She will maintain minimum highway speeds on most hills and on long grades you will do just fine in the climbing lane with the other trucks. Actually, low speed rear and overdrive can keep you in the travel lane more often.
Last edited by Jim Sears; 05/27/2017 4:21 PM.
