Wrong Balancer Bolt?

I was installing the harmonic balancer on the 383 this morning (forged crank) and noticed that the retaining bolt bottoms out before the balancer is seated all the way in. It will only pull the balancer in to barely reaching the timing tab on the cover. Could it be that I have a bolt for a cast crank balancer and they are a little longer? The one I have measures 2.2 inches from the bottom of the head to the end of the threads.