I am going to buy a 69 Thunderbird for $400 to part out. The seller says it has a 429-460 with a C6 transmission. I assume he doesn't know which it is but I don't know much about these either. Is this something that would make a good engine for a hot rod or just big and heavy? Anybody ever build anything with one of these? It's currently not in the car so I'm guessing it's got something wrong with it.