panic: So the difference is in the Rubber compound? Harder for higher vibrations and softer for low frequency shaking? If that is so then there would be approximately 3 and maybe four different variations? 1, 216. 2, early 235, 3, late 235(maybe) and 4, 261? Is there a part number difference that matches the thinking? You have answered my question about the "damping" function and thanks for that. Balanced crank shaft has both mass and rotational considerations. Damping has only harmonic issues as I understand. I get stuff wrong all the time. So If I an wrong let me know.
