I have never swapped one, but have heard quite a few times that the Mounts are different on the Cabs between the two.
Up to now, I really can't actually remember any Pick-ups riding around with a former 2-Ton Cab.
But that said, I'm sure it could be modified to fit. But me personally, I'd want a Pick-up Cab on a Pick-up.
The Floor Hump is also another issue as mentioned, unless you would need one anyway (like I would, lol).
Bill