Thought I had mentioned someone talking about dual vs single pattern selection in a paper or video. It was in a video I saw several months ago. The guy is talking about the selection based on on Exh/Int flow ratio of the heads. His breaking point was 75%. Anything above go single pattern, below go with dual pattern profile. Think it may be his personal rule of thumb. Don't know anything about the guy, just ran across his 2 part video on cam selection. He does mostly talk about Fords and Chevys but I would think the basis of air flow would apply across the board. He did say cam lift should be determined by head flow but I think that was in part 1 of the series.