[dsraven]

I was a heavy duty mech for highway trucks for awhile. driving an empty truck is called "bobtailing", nobody wants to do that as it is quite a rough trip, especially with springs and not air bags like most modern heavy trucks have.
if you wanna haul heavy stuff, like a regular dump truck, then you're gonna need a modern regular dump truck chassis under it with the powertrain to match. otherwise, if you like the look of a dump truck but rather like the ride of a regular truck then maybe convert it to modern 1 ton underpinnigs. yes, it won't have the look or function of a dump truck as far as weight hauling, but ask any modern dump truck driver if they like to drive their work truck after hours just for fun......nope would be the come back, pretty sure.
maybe think about a solid axle up front, if thats what you want, with power steering, then an airbag suspension out back with a modern axle ratio and a modern engine/trans combo (with overdrive, automatic etc). that would make it driveable for short trips etc. if you want the big truck look and feel then use a modern big truck underneath, but go for the air bags out back if possible. there are loits of 2 tone modrn trucks with decent ride capabilities and you likely see them driving down the highway. ait, tilt, cruise, locks, windows, power seats, etc etc. get one of those and stick the old body on top if thats what you wantm a work truck that drives ok and doesn't just rive you from chiropracter appt to chiropracter appt.lol.