We bought a used 1995 chevy 3/4 4x4 with 73,000 original miles.
It has a 5.7 non-vortec motor.
Just daily driving its run fine. Hook any size of trailer behind it, it start heating up. (210+)
We took the radiator out and had it clean, and put a new 180 deg. thermostat in it.
And it still does it. The radiator guy said the raditor was fine.
chevy 5.7 overheating
