Add hotter cam or Add hotter head ?

I take it you've never done it.
You'll have to explain how it won't make power when it flows better at every lift with the same cam. For some reason.. I think even the tv crap shows have done it.
I have a truck with 311k on the stock short block that after tossing on some purpose ported heads feels like twice the engine it was.. and now rpms higher=hp why? It now has available 10-40cfm per .100 lift.. As for stock cam range/rpm...the valve springs are one of the main hindering factors of squeezing all RPM you can..and after running 50 years.....they're toast.
Stock teen runs 85 seat and 180 open, maybe . You need at least 250lbs open load to turn 5500 with .450 lift and not encounter spring spin/bounce boogaloo.
If the head can fill that same cylinder more per .100 lift and the Springs are upgraded to allow it to spin up and use the entire range of that cam 'which is a little bit more than it says' .....power increase.
I'm not doubting an increase from a head alone.
I'm saying the right cam selection will produce more power up to a point over just a head change on a stock cammed block.