Hmmm , yeah I have actually seen one of my crankshaft noses get bent .010" out of allignment after big backfire, and that was with a stock vibration damper on it, but it must of weakened it because the next backfire split the damper through the keyway hub and everything just basically fell off. That was with a 355 chevy, so now looking at the 383, would the trick be to go for the SFI internal balanced damper as it will keep the safety guys happy ?