1992 Dodge Shadow Head gasket

My father had head gasket replaced in his 92 dodge shadow @ 128000kms, aprox. His engine started overheating, so the thermostat was changed and same thing still. There are no normal telltale signs of a blown headgasket ie: oil antifreeze mix, white exhaust, leaks or anything else. I know those motors had head gasket problems. Everytime he drives his vehicle short or longer distances it keeps overheating. Is this another headgasket Problem? His milage is now 178000.