1990 jeep Wrangler heats up and shuts off.?

recently having problems with my Jeep it will start up fine run for a while then shut down. I notice the temp Gauge go up to about 220 degrees then the jeep shuts down. It does all this in a matter of 30 mins. I changed the fuel pump, cleaned the carburetor completely, changed the Thermostat and housing (which i over torqued) and flushed the anti-freeze.I don't know what else to do or what it could be...