if you have title to both cars, swaping parts it legal (many cars have the vin plate attatched to the dash itself, so a dash swap would change the vin) basicaly, you can leagaly take two cars and make them one car if you own both cars. If you ever have to go through a theft inspection they will look at all identifying stickers on the car (dash, firewall, fender and bumper stickers. If it's an airbag car, they will check all the airbag components too. EPA stickers can be ordered from the dealer to replace one that has fallen off or been removed for paint. If you have legal title to donor car, all parts save for air bag parts can be swaped and those with vin stickers require you paying for a new sticker during the thieft inspection, at least that's how it works in NY.
You live in Florida though, the state of DMV fraud. you can get away with most anything there, all the laws are full of loopholes (pretty much on purpose too). Every illegal car I know of that's been imported into the states has gone through Florida.
Old cars like ours are not that hard to do a total swap on, just make sure you get every part that's identified. If you do a perfict job, the burden of proof is up to them to prove if you get caught.
The penaties are felony charges though in most states I'm sure.
