[cabmandone]

Can't speak t a dually but a friend and I were able to lift the bed off of a F350 and we're not built like the Hulk.
OH! and if you have to grind the head off of the bed bolts, put a piece of metal over your rear window... I won't say why out of embarrassment, just take my word for it. And if you can see the bolts from the bottom, spray them for a few days with Kroil or PB Blaster before you try to back them out.