I would say if it is an unported head, then they should be cleaned and checked. Usually just a bit of port cleanup and good valve job will improve airflow quite a bit.
The Trick Flow heads are CNC ported and they were good out of the box. The Koffels ported B1 B/S heads were good out of the box. The Hughes Engines Ported Max wedge Victors were good out of the box.