OEM balancer or fluid damper?

Me too. I got a Fluidamper for my 421. When I worked at Summit, we had a company come in and give a sales pitch for their balancer, and they said it was superior to the Fluidamper because the Fluidamper only really controlled vibrations above a certain RPM. How true that is, I don't know, I never really looked into it, but they were saying it was no good for the street. Sounded like BS to me at the time, but...