225 slant rebuild for more power

A six is a six and never going to give you any real power like a small block V8 unless you spend a crazy amount of time and money on it.At 17 years old I'm guessing you can't do that .What I would do is pull the motor out and just freshen it up with a timing chain , rear main oil seal ,all new gaskets & freeze out plugs .Put in electronic ignition and a good rebuilt carb and use it as it is.Enjoy it and take care of it slowly fixing it up .A Valiant wagon is a very sought after car so enjoy what you have while it goes up in value then sell it when you are older and know more about how to do all this . What you will get from the wagon will give you what you will need for the next one down the road and you will have way more experience and money to build what you want .