Hi, Ed. I'm very interested to find out if you attempted to replace the Class 5 flapper with an aquapiston. I'm considering a Kohler Highline with a class-5. It seems that the Aquapiston is more highly thought of by many reviews. I was sorry to see you got no answers to your query...just wondering if you ever learned somewhere else or by just going ahead and trying it. -Joe Phoenix, AZ
