We don't have a number for cylinder head temperatures. We simply don't use them. We adjust the engine by how it's running. With a 25:1 fuel/oil mixture, you have plenty of lubrication. As long as the engine is set rich of peak RPM, and is running well, your temps will be OK, no matter where they wind up.

Again, we don't use temps at all to set the engine. Maybe once we've found the setting that works, we'll check a temp out of curiosity, but we don't use it to confirm whether a setting is "good" or not.