Dan, I had used an ATI harmonic damper, but it would weld it self to the crank, I then went to a fluidampr and my problems went away.
I talked to ATI and they would not give me any help, I thought the rubbers were wrong, and I was right,in talking to Glen Self he said that you need number 88 rubbers for an inline.
Also I am one of the few that use a forged crank, it flexes more but won't break.
The old catalogs from ATI used to show the ATI vs the Rattler vs the Fluidampr it showed the Fluidampr was the best to 6000 RPM then the ATI was better, the Rattler was the worst.
ATI no longer shows this chart in their catalog.
Hope this helps
