when we people around here talk cams, we mean advertised duration, and by the way you can make more power using open chamber heads (less valve shrouding) just have the heads milled to the desired compression ratio.
We people?? HHmmm.. Thats the first I have heard that. And that's not true about open chambers, you can make tons of power with closed chamber heads, it depends on what else you do with the chamber as far as porting, unshrouding, etc...Milling the heads can only be done so much, then, as Pat said, you get into p/v clearance issues, intake not fitting, etc...a whole host of problems. Open chamber heads only came around because they supposedly run 'cleaner' on the smog engines of the early 70's...it was done for smog reasons, not power reasons.