I want to soup it up to 300 hp horse power from stock 170 which i am rated at. What is the best way to do this? or most economical way? Should i invest some money into basic lings like a tune up and new belts first? Anything else i should buy or consider buying before performance parts? any help or input would be super appreciated!

Your looking to almost double your current HP.That means an entirely different engine.To be honest,the 330hp GM crate engine will be your best bang for the buck.