I asked because there is more to cylinder head selection than materiel. Personally, I'm not a fan of many closed chambered heads, especially the stuff Chrylser used. If my choice is an iron head with a chamber I like or an aluminum head with a chamber I don't like, I'm taking the iron head every time, even though I hate grinding iron.
I say that again because just using air flow off of a bench to determine how much power a given head will make is sketchy at best. I've seen heads that flowed like crazy, but didn't even make 1.7 HP/CFM and I've seen heads that didn't flow very well that made 2.3 HP/CFM.