Help!!!!

[Number1]

Default Help!!!!!
I have a 1985 Monte Carlo as with a 5.3/4l60 swap. It has factory accessories except an ls3 Camaro5 water pump. I'm letting the car run to get the car up to temp to make sure the fans come on. As I go to check under my hood I notice that my radiator is extremely hot and my upper radiator hose looks like it's about to burst and it's also extremely hot as well. While my lower radiator hose is cool. Could it be a defective thermostat? WHAT AM I MISSING? PLEAS HELP!!!!!!!😭😭😭😭😭😭