Headers for a A body

The scavenging tunes for much higher rpm, so you miss out on some low-mid range torque. Still an improvement in flow over manifolds, but I wouldn't take off long tubes for it.
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