I back flushed my heater core through the lines in the engine compartment. Did this a bunch of times, back and forth, till the water ran clean, and steady both ways. Then I flushed the entire cooling system till it ran clean. Emptied the entire cooling system. Filled it up with new coolant, and water (as per the Chrysler specs). Started the engine, ran it up to temp. (thermostat opened, coolant dropped), added more coolant/water (in the over flow bottle too), put the cap back on (I'll check it again when she cools down). Car running, heater/defroster, and fan motor on. Lots of heat coming through now. Heater core lines are both hot, and hot. I think I've licked this one.
Thanks again everyone!