That was me who posted about the 5 CFM . Had a friend port my heads and he went to the Mondello school . Did some BBC and the 6.5 heads for me . I have never seen any numbers from Chris on his ported heads . If you are in the business of selling 6.5 heads , why wouldn't you post some numbers ? The interesting point about this thread is that everyone talks about boost but really that engine will probably run NA most of the time . There is a point that you switch over from NA to boost but how does it run in between that point ? If you have seen WW's posts , you will note the higher stall conv to go with the AAT . I can tell you that the stock open plenum manifold is worth 20 CFM over the dual plane manifold and the open is just under 200 CFM . My heads flow more than that and would require a different manifold as well .