I've never really understood the attraction to changing to a later model frame; they are totally different. The frame in your car could be a good candidate for a Mustang II or even the stock axles can be made to handle and drive fairly well.

Another thing that frightens me about frame swaps, you are really pushing the limits of being illegally registered if you are running the old title. I've seen a couple of cars that were impounded by the state patrol for similar activity.