i have a 93 f150 it has the 4.9 300 in it. used to be my fathers so I'm fixing all the issues he had. my current issue started about 2 months ago. my heat gauge (dummy gauge) would shoot all the way hot then cool but only once between start ups. my first thoughts were head gasket new water pump due to age and and thermostat. i was then told by a tech at my job he thinks its a radiator. so the parts i currently replaced is the thermostat, the radiator 2 hoses and the water pump. after this the hoses get over pressured and weeps out of the radiator cap. so i tested compression and used a scope on my cylinders to double check on head gasket. everything good and no hcs coming from the coolant. the heater lines would feel over heated compared to the upper radiator hose which would always be hot but you could hold it. you could also pop the radiator cap release the pressure and put your fingers in the coolant for a good 3 mins before the engine heat would circulate around the fluids (engine off after an hour run) we then pulled out the thermostat and the weeping stopped but the hoses still get over pressured. also before removing the thermostat my temp gauge would move just to the n in normal which is not normal for this truck. any thoughts about this? my college instructor says he's never seen this type of issue unless it was a head gasket but he did all these tests and everything points away from it.