Newbie needing answers!

Hi everyone I'm Tmac. I'm new to mopar or basically hot rodding in general. I'm looking to purchase my first project/weekender car. For reasons unknown I've fell in love with early 70s darts. Other car guys I know think I'm crazy and that I should stick with Novas and Chevelles. Anyway I found one in GA and I just want to be sure it's not too crazy over priced. Also it has the 360 V8, the owner is saying around 225 hp. What would it take to get closer to 500 out of those motors. Give me the hard truth!

1971 Dodge Dart for sale near Canton, Georgia 30114 - Autotrader Classics