95 riviera..overheating

workin on a 95 riviera..just changed the thermostat,but shes still runnin at about 210-220 degrees on stock guage on dash...does this car take that dexcool coolant or regular...anyone know? fan works...could I have an air bubble trapped in there maybe..?its got the 3.8 sc motor in it,runs great..just gets hot...we did have our 1st 100 degree day yesterday ,but it seems like it shouldnt be gettin that hot...fluid level good,water pump not leakin either...any ideas would be great..thanks

could be an air buble or some of your hoses might be colapsing. Bleed your radiator and change the hoses. Did you clean the radiator?

thanks for responding!yes I just cleaned the cooling system and changed antifreeze,still runnin hot. Then i noticed the heater core was bypassed...would that make it run hot,not going through core?