you changed a internal component, bite the bullet and pull it apart and get it balanced.

I have had two engines (that i know of) on the dyno that the owners didn't balance. once i felt vibration on the 1st pull, dyno session was over after playing 20 questions.

IMHO if you pull it apart, I would get some aftermarket rods and a balancer. your engine will rev faster and have less stress on the bottom end, lets face it those rods are at least 45 years old.


Joe