[MusicMan70]

Hey Todd,

your 305 does not have a harmonic balancer. It's more of a flange that the pulley bolts to as well as having some markings for timing. This engine is internally balanced.

Perhaps you just have some or one bolt(s) loose down there...

If the flange is damaged you may have to go junkyard or the parts for sale on this site... Hope this helps, Henry