i do feel dumb for asking, but i really want to know how it works.... is it just the fact that you have two transfer cases running different gears to the front and rear??? so you can have the front at lower gears and the rear at higher... please, someone help me out...

military_stang

Are you thinking two cases, one for front axle and one for rear? Dual cases is the low range box of one case bolted to the tranny, then an adapter, then a whole t-case bolted to that.  The front case is just hi- neutral-low, the rear case has every thing. For crawlin you'd put the front case in low and the rear case in 4-lo. The reason for duals or duals with 4.7's is for slowing down your rig to climb easier.   Shambs explanation is good.