Headers for a A body

I'm been reading on how to improve the volumetric efficiency. Don't good heads help along with a good exhaust system, what about the intake manifold and air cleaner housing. I know that the car isn't home yet so I thought I would take this time to learn how to improve its overall performance. Improving the volumetric efficiency is a good idea even if it runs good? The first thing to do is to make sure it's safe to drive. Thanks everyone for your help
I believe you're over thinking it. Buy the car, make sure it has a good tune in it and enjoy. If you want to upgrade, make a plan, then start accumulating parts to achieve your goal. When you have everything needed then tear into it.