All the dually wheels I have seen are made for 8 lug wheels. So you would need a 1 ton rear axle. If you want the axles to match, then a 1 ton front axle would be required. And the frame is wider on the 1 ton. 3/4 ton stuff might work though. You can tub the bed like hot rodders do for wider wheels.
The problem is that trucks are already light in the back and unless you are doing it for looks or to add a load, you will end up with less traction.
