I have an 84 F150. If I were to say, get an F250 of the same generation with a rotten cab, but wanted to swap the cabs, could I put the 250 Vin tag in the 150 cab? Paper work is in the picture, I'd imagine. Thanks in advance!

 

I did the opposite.
Put a F150 cab on my '83 F250.

I called the state and had a new vin created. A state trooper came to the house and checked it out and put a NH VIN on it. It was a bunch of years ago so I forget all the steps. But technically and legally that is what needs to be done.

But what you actually do is up to you. Remember if you use the F250 tag you will be paying more in registration because on the books the F250 hold more and weighs more than the F150.