Ok so I have noticed a few times lately my truck wwhen going up a long hill under a load, when im on the throttle it starts getting real hot, way too close to the red for my comfort level... I have sprayed out the radiator to gget the bugs and mud and shit out, checked the fluid level and its full. Its just getting to summer and I need this truck to be reliable, what do I do to keep this beast cool? I was thinking next ill flush the radiator, but idk if that's it or not...

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done