Okay, here is my problem. My 97 FZJ80 (12x,xxx mi) will overheat when going uphill in snow or long, steep climbs at around 20 mph. I have no problems on the street or with it idling through rock gardens. I have replaced the fan clutch (again) and flushed the coolant. I’m not blowing bubbles or have any white smoke. The rig has had shady maint until I got it a year ago and I wheel it hard. My question is, based on your experiences, is my problem more likely sludge in the radiator or a head gasket starting to fail. I can’t afford to replace them both (though I’d like to), so I would like to take care of the “most likely” suspect first. Also, am I overlooking something that it could be? The rig does use oil (about 1qt every 1500 miles) and it has seen time in both the red on the temp gauge and bouncing off the rev limiter, just not at the same time… TIA