ok, here's the deal guys, 30 years ago the gasoline was a world different than what it is today. todays gasoline makes these engines run warmer under load aka free way speed or climbing a hill
the fan clutch is fine because you said it cools right down when you slow down or stop
the fan clutch going out would cause the engine to boil if you slowed to a stop
what you need to do is get rid of the old 2 core radiator and get a 3 core radiator, dont let the idiot at Krager or Autozone tell you they were not made because they were, Marlin has a 4 core diesel radiator in his 80 truck
I have a 3 core V6 radiator in my 79 truck ( i have a 2 inch body lift required since the v6 radiator is 3 inches taller than the stock 79-83 radiator)
