Harmonic balancer 340

So I measured the balancer. It was 2.75 from cover and .5 from timing marks. So I think its close to 3/8 off. I removed the crank bolt and the threads have minor damage. Do I need a special tool to remove the balancer?

How long is your crank bolt?

How are you installing the harmonic balancer? Are you sure that it's seated all the way?