2x4 to 4x4 Conversion on a 1999 5.7L Automatic Transmission C1500 Suburban

:screwy: this might seem like a weird idea but its seems pretty logical to work ok i Have a 1999 Chevy Suburban 2 wheel drive 1/2 ton 5.7L 350CID Automatic transmission was doing some research on the truck took the dash off an found out the wiring harness is there for the electric 4x4 shift buttons an it is also laying on top of the transmission with a weather pack connector cap on it sealing it but it is there an unused so can i just go out to a wreck yard or get 1/2 ton front an rear differential's off of a 1/2 ton 4x4 silverado or a yukon or tahoe or another suburban since all the parts will be the same since all these models have basicly same structure of parts i know i will need the transfer case with the electrical shift capaibilites the shifter buttons to go in the knock places in my dash an the front an rear drive shafts an brake hoses etc i know what all i need an have the idea to do it but was wundering if some body knew for sure it could be done i mean is the frame all ready ready to bolt up the new axles etc? i would appreciate all the help i can get thanks