you can reverse the rear tires with no problems, but the fronts will cause the handling and steering to suck, mostly on pavement though, as olds mentioned not much different off road.
Off road you will gain a significant amount of byte. This may sound good but it puts a large amount of strain on the drive-train. The lugs are going to try an dig in deeper. On the stock tires the lugs are fairly far apart and will dig in unevenly causing on power squirlieness. In the event that a lug catches on a embedded chunk of rock it will momentarily stop that wheel until the rest of the drive train catches up and moves the truck forward. This can cause havoc to all drive-train parts and will cause things to brake or wear out sooner than later. Its like running paddle tires. Works great in the sand and snow but isn't recommended for other surfaces.
Not recommended for everyday driving
Can I ask why you ask this question?
Did you mount your tires backward on accident like most of us have at one time? :
Eddy, I did not notice a signifagant increase in bite off road, a slight bit maybe, I did notice the handling really sucked. I did it on purpose just to see what the difference was for myself, I quickly put them back on right and never looked back.