Most popular head casting/chamber design

I have a few slant 6 heads laying around, early , mid, late. I'm going to port , rebuild,flow and sell them. Couple will have big valves, one stock size. The stock size ported intake will probably flow around [email protected] when I'm done, the big valve versions in or around 190-200 cfm.
I wouldn't wanna waste time on the wrong heads. I do plan on selling these, fully machined, valve job, guides, and springs for .500 lift stuff. Inquire later if you're interested in one.

Let's hear which casting and why, thanks.