All the above.
No matter what head is on top, the stock cfm of the head is the limiting factor. This, most of know. Now with anported head on top, stock, EQ or Edelbrock, it doesn't really matter because the engine doesn't care what head is on top but it is only responding to the flow ability of the head or what's delivered.
While one head will flow more low, less high, or what ever, just the increase of the (known) flow is what is of intrest. And how far we can go. Is there such thing as to much head flow? I guess that depends on the parts used and application it is involved in.
Where is that with this engine and camshaft? And where & what do we end up with?