If I'm understanding you correctly, you're saying that the damper won't press fit all the way back to where the rear of the damper "thunks" against the crank gear. Is that correct? Is this an aftermarket damper? There have been many of these abortions made in China and other "offshore" locations around the world. They might have had the bore in the damper hub cut to the correct diameter to press fit onto the crank snout....and then again, maybe not.

.