The heads have nail head valves and a small mill down to 63cc. I can try more timing again although I don't think that helped. I am having an issue (I'm full of them trying to get this car on the road) where I set idle at 700 rpm and then by the time the engine warms up its 1500 rpm. This has happened multiple times so there is something going on....maybe to do with a fuel vaporization issue.