Sorry to hear about your overheating condition , sometimes it's hard enough keeping a 4.0 from running too hot as it is. Want to say that no one should ever run an engine without a thermostat as al that will do is just let hot water get hotter without letting the liquid in the radiator cool while the thermostat is closed . Thank goodness your not finding damage such as oil and coolant mixing , hope that never happens to you. I would say to just run hot water through the system until its clear ( I don't like radiator flushes , hard to completely rinse them) but your radiator and heater core sound like they are clogged . Disconnect the heater hoses at the firewall and see if there is any chance of clearing out the stop leak if it did not totally congeal. Keep an eye on the firewall condensation drain ( for a/c) to see if any coolant is coming out which would mean replacement of the heater core. For that , you got to get under the dash , I prefer to just pull the dash. As for the radiator , I don't think they boil out the ones with plastic tanks on the sides , might mean replacement if can't be boiled out if that is where your leak was originally . A lot of times those plastic tanks are the cause themselves. Sorry to bear less than good news but we would rather have you get a new heater core and radiator than see you cook a good running engine. Hope this helps. Greg
P.S.- welcome to Jeepz.com and thank you for your membership . Wishing you well and that all works out well too .