318 Upgrade

First complete your assessment of what you have.
For example: What's under that K&N with the filter top?
Drive it. See how you like it. How it stops, accelerates, mpg, etc.
See what you like, whats annoying, what if anything really disappoints.
Then go from there.
A stock 318 2 bbl can be pretty snappy at street speeds.
4 bbl can help a bit with passing on the interstates, and most certainly on the dragstrip.
But for around town or even regular highway driving a 2 bbl is not bad.