Yep, every state matters. In OK, the politically correct legal way to do swaps is to take both title to frame and the title to cab to the Tax Commission, they destroy or junk those VIN's and reissue a state issued VIN #. Now who wants that? NOOOOOOOOO. It would have nothing to do with the year, make, model, where built, engine size nothing. So I carefully removed a VIN tag and kept the OEM rivets part of it, opened up the rivet holes just a **** hair and glued it back down. Can't even tell. Then I did scrap the bad cab and frame to match it. So in my case, it's all legit but the state wouldn't be happy about it. Swapping a cab shouldn't be any different than swapping a hood or fender. I doubt I'd ever have a problem since the VIN tag matches the frame VIN.