[Your41Plague12]

The 84 cab will bolt right up. Is the 84 cab a 4x4 as well? You need to make sure it has the high transmission hump rather than the low one. It will have the high hump if it is a 4x4 cab or a 2wd cab with a 4-speed. You will more than likely have to swap the whole wiring harness. It's not that bad, to be honest. It's really all plug and play. Unbolt the wiring harness from the engine compartment and unplug everything. You may have to cut and re-splice the rear light wires, but even if you do, it's easy. Two long sheet metal bolts hold the fuse panel to the firewall from the inside. Then just disconnect/unplug everything inside that needs to be unplugged, and swap it over. Plug it back into the engine bay harness when the cab is on the frame and you should be good to go. One more thing you may have to cut and re-splice is the dome light wiring (I had to on mine, swapping an 84 cab onto an 83 frame) but it is easy as well. Best of luck, and post some pics. We'll help you through. I just did the exact same thing, so if you have any questions feel free to ask.