My concern with the driveline was mostly related to the wheels and finding viable tires. That being said I was at a car show today where there was a 1950 2 ton truck that had the original type wheels and tires. I talked to the owner and he didn't have too much trouble finding tires or a place that would mount them.
He indicated top speed was about 55 MPH but it needed to be a smooth road as any bumps and you are bouncing off the roof to the cab.
