Horse Power Potential of Cylinder Heads

Budget is limited of course. I'm doing a 4" stroke 340 forged bottom end. 16cc dished pistons at zero deck should be 10.5 to 1 comp. Trying to figure out how much head flow I need to reach the full potential of the engine. Not a race engine just a fast street car good torque broad power band set up. Car has 3:55 gears auto trans. Will use TTI step headers and probably rpm manifold. Will spend the money to get what I need but don't want to spend more than I have to. Plan to do hydraulic roller cam so max rpms will be a little over 6k to be safe.