I have seen a posting on this before. I have a 350 chevy motor with problems with the bolt the holds the harmonic balancer. It appears that the bolt threads on the crank may be gone. I understand that the crank is hardened, is there something that I can do to make sure the bolt is secure. I tried a longer bolt but that did not work.  thanks  

You have to rethread the nose of the crank. You'll probably need to take it to a shop and let them do it, since a pretty heavy duty tap is gonna be needed.  

Thanks. Are they going to use the same size tap or are they going to have to go to a size bigger? I have an industrial tap that is the same size of the bolt. It is a bottom tap that may be able to pick up what is left of the blind hole.