That ATI BB balancer hub is like all the other stock hubs on BB Mopars, your good.
The bolt you need is a .750(3/4 inch x 16 thread x 1.5 inches long works well, make sure and buy a good quality thick washer to use between the bolt and the dampener hub You want the bolt threads to be engaged in the cranksahft threads at least the diameter of the bolt
Is your motor still externally balanced? If so you need the external balancer, I have had one on order since May of this year, no luck so far