The valves do sit in the recessed area without the square shaft installed. The cylinders are Brand new shiny, just back from Millinium Ent for nicasil.
I have bead blasted the RC valves (4) to clean the carbon off. I'm suspicious that some of the nicasil plating has changed the clearence within the RC valve recessed area in the top of the exhaust port. There is absolutely no carbon, oil, or anything in or on these cylinders. I might be able to post a picture if it would help.
Mark