Denny, looks like you've tried everything and then some.
Is it possible a brake drum may be out of balance? I really wouldn't see how, but never know.
If changing tires and rims didn't change the hop or the speed at which it occurs and goes away then what about the axle itself? Could it have a slightly bent axle? (And I'm just throwing something out, you may have checked this)
Is the axle in proper alignment with the front end? (Again, you may have already checked this)
But I don't know if I would spend money on beads if different tires and rims didn't change anything. I guess if it does work you would be far ahead.
Be interested to see your results.
