5.9 Magnum to replace Older 360, flexplate?

Oh, I see so one knocks the weight off the converter to make it neutral, since the flexplate for the magnum has a weight for balancing, right?

Yes, exactly correct for 5.9 Magnum.

The 5.2 Magnum was internally balanced from the factory, so it does not have weight on the converter, flextplate, or harmonic balancer. They are all neutral.