I took it apart and researched it then and your right about the years and the identifying marks, I'm just wondering if the earlier forged crank balancer can be used on the later forged cranks ?
Yes. The forged crank dampers were all neutral balanced the same. Only the mark on the damper ring was in a different position.
So is the engine running evenly? I'd run a compresison check, look at all the plugs, and listen to the exhaust pipes when idling. To detect any un-eveness.
Under what circumstances does this vibrate? Idling and all RPM's? Mid to higher RPM's only?