I just picked up a 1977 ford f-350 2wd flatbed truck, 4.10 in the rear and a 390 (yet to be verified) the truck used to be a u-haul truck, The parts of the cab that are in good shape are great, the few rusty spots in are not just rusty, they are rusted through and need some major work. Such as above both front and rear windows its rusted out in several places.
At my parents house i have a cab off a a 76 f-250 4x4, does anybody know if these cabs are 100% interchangable? If the other cab is in considerably better shape i'm thinking of cleaning it up and painting it and swapping them.

 

Only 2 issues First would be in the rear cab mount. I'm not sure what the Frame width at the rear would be on your '77, but the highboy will have the mounting pads to the outside of the frame. All I did was to bolt the front in place and align it with the front sheet metal and then drill through the existing mounting holes into the cab to match it to the mounts on the frame. I went from 2wd cab to 4wd Frame, so just the opposite of what you are doing. It was not a big deal. Next up may be in the trans tunnel. Both of mine were removable, and I've heard that not all are, so that would be something to check. One additional would be Auto vs Manual tranny and the component swap involved for those. Otherwise once you swap all of the wiring, it's a piece of Cake!

 

I was under the truck today and i think I remember seeing the mounting pads on the outsides of the frame rail, so i'm hoping that wont be an issue. though i'm still not sure on the frame widths. The trans tunnel on my new truck is removable.... i removed it today. however I'm not sure about the other cab. I need to just get off my *** tomorrow and go over there and load that cab up and bring it over here so it is at my disposal. Also new truck is 4speed and i think the other one was auto.