The $3k you have to "spend" will very soon be gobbled up by miscellaneous expenses of two project cars.
If I needed some fun transportation I'd go with the Falcon as is and drive that little fellow for years. By the way, the car had a straight 6 engine, not a V6.
The Nova sounds like a cast-off wanna-be racecar that needs more attention than it deserves.
The 55 project, 2 or 3 years or not, is worthy of concentrating on. So, if you don't actually need transport, spend the $3k on the 55!