I had pumped the Delco sealing tablets through the heater core as was recommended and it worked great -- for a month. Thirty-seven days has gone by and the small leak is back. Looks like I'll be pulling the dash.
Delco sealing tabs/stop leak is a temporary solution and not really recommended.
If you need a new Mopar thermostat or new hoses, now would be a good time to replace them.
With a new heater core installed, make sure you flush the entire system well afterwards.
Then install the the correct Mopar HOAT or Zerex G-05 coolant.