1999 Dodge Durango smoke / coolant smell from vents

Sound like you get the great fun of replacing the heater core. When this leaks it will leak inside and you get to smell it and it smell bad too. It could also be a heater hose or connector to the core. So I would buy the core and heater hoses and clamps so you have everything you might need and if the hoses are even questionable just replace them its not worth skipping as this is not easy to get to anyway. Here is what the core looks like.