the classifieds in the newspaper, or the stang trader. Try
www.autotrader.com. these are the best ways to locate them. when you find one you like, check it out theroughly and then ask around to people you know, it they think its a fair price. There is a lot of people out there who try and get back what they put in and that doesnt happen with classics. I know a girl who's daddy paid 10k for her 65' 6cyl (haha) what an idiot.