The actual number seems to be lost to history, but near as I can tell there was either 4 or 5 440 4 barrel cars and one 383 automatic. One of the 440 cars was immediately cut in half for certain camera angles. The 383 car did the towing of the Camaro into the dozers. The rest were beaten to death shooting the movie.
There were no survivors.
Chrysler made sure of that. Word has it that Mother Mopar was so upset by the nudity and the drugs in the movie that they took the cars back and smashed them so that they would not end up in any auto shows.