I have a 72 240Z with an Auto Trans and a 76 280Z with a 5 Speed. The 240Z is not running now b/c of the carbs, but there is virtually no rust. The 280Z has tons of rust, but a really strong engine and trans. Could I make the 240Z a faster, stonger car by changing the transmissions? Or, is the auto good enough. Like I said, I have never driven it?