Thanks for the reply MrPbody. Your concern for the risk of disagreement is well founded.
I believe what we have here is a case of semantics. The heads do have an open appearance, however are well described as closed. I agree that there is a larger quench area than the BBC, but the effect is virtually the same. Also, Ford has catagorized them as closed. From a purely engineering standpoint, I have to agree with you. The shape of the Chebby chamber more closely fits the classic standard.
It sounds as though you may have some experience with comparative head engineering. May I inquire as to that experience, as you've mentioned "we"? Please don't tell me that you stayed at a Holiday Inn Express last night!