I have never looked that close at a manual, BUT, I have changed multitudes of clutches over the years and never had an issue. That said, I would assume it may be marked if it was a completely balanced rotating assembly but, once the flywheel has been resurfaced, I bet the X is gone! If you have noise coming from the clutch, with your foot off the clutch pedal, it is more than likely because the throwout bearing is hitting the clutch and causing chatter. There should be just enough play that it should not touch the clutch as the engine is running, unless y our foot is depressing the pedal to dis-engage it.
