So my '91 1500 has been overheating. I just replaced the thermostat and flushed the radiator and that helped a good bit, but it didn't fix it. The thermostat is set for 195 and the truck will stay around there for 10-15 minutes, but it seems to just give up out of nowhere and will get up to 220 or so before I have to turn on the heat. Any ideas?

 

Is the radiator clean? They can get pretty gunked up and not allow any airflow through after a while

 

I'm not sure how clean it is. Was already leaning to buying another one, so I probably should