[olddog]

The only thing that matters is, how was your engine ballanced when assembled? In honesty it could be either or internally ballanced. It just depends on how it was built.

I would recommend having someone, who knows how, to verify what the damper that comes off is.

Some purrests say if you change the damper the engine should be pulled apart and all components ballance together.

I wouldn't change it unless I was certain that it was the problem.

Could be a clutch, as well.