Distributor problem, if you have one please look.

[Mopar-Charger]

Good idea. That might explain the 15 degree jump in timing mentioned earlier. I can't remember exactly but I remember somebody recently talking about their balancer. It was so bad they could turn it by hand.

Hmm, I can do that. Where could you get a positive stop?

 

[Shorthorse]

Jegs, Summit or even Auto Zone. You want the 14mm.

 

[ckessel]

I made mine out of a gutted sparkplug with a 3" or so piece of 1/4" allthread and a nut at each end to adjust/lock down the allthread. Didn't have to buy squat and recycled at the same time.

 

[The Horvaths]

Instead of two nuts, i made mine from a gutted spark plug, some J*B Weld, and a bolt with the end ground round and smooth. I used an oiled bolt to cast threads into the epoxy. A jam nut holds the stop bolt in position.
I often cast threads in epoxy. Lube the forming bolt well and let it cure before removal.

BTW: if you can turn the balancer ring by hand, or if it is loose at all, replacing it is the prudent thing to do. They have been known to come off. You don't want it to come apart at high rev's. Or at any rev's for that matter. They can do some alterations to whatever is in their path.
A more likely scenario is that, as the damping material deteriorates, they lose balance. This can cause vibrational stresses that shear the crank bolt or even damage the crank itself.