Flywheels are usually pretty good. It is the clutch that may be out of
balance. If I were you and really concerned about balance I would trust the
engine, get the flywheel balanced, then put the clutch on it (marking position)
and balance that too. Since the clutch plate doesn't necessarily rotate with
the flywheel, it doesn't need to be balanced with it, as any imbalance in the
clutch plate will just screw up the balance job of the clutch. Also locating
the center when not assembled to the engine with pilot bearing will be difficult
if not impossible.
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George Downs Bartlesville, Heart of the USA!