Mild 340 upgrade ideas?

Starting with a low compression fresh .60 overbore 340 out of a 73 Challenger. It's built to stock specifications by previous owner and I was wondering what would be some of the easiest/cheapest modifications to increase horsepower and update the engine a little bit.

Ideally I'd like forced induction via a junkyard supercharger someday, what're some steps to prepare for that? As for funds I'm a college student with a part time job and a penchant for dumpster diving.

Thanks in advance guys! You're a great community that I'm glad to be a part of.