I’ll posted last week that I had some work down by Ozark Outfitters (great guys). While checking over the motor, they sent these pics of the radiator. Wow, although I check the oil weekly, I’ve obviously neglected checking the coolant. A local mechanic addressed deleting coolant flow to the rear heater one year ago. Ozark thought maybe they used the wrong antifreeze or the mix wasn’t right. Anyway they thoroughly flushed the system including removing the radiator and cleaning it, changed all hoses and overflow bottle and used red antifreeze. I drove it 3.5 hous home at highway speeds and have driven it daily around town since. I just checked it. Radiator fluid looks good and oil level is still right on the full mark with no froth. Maybe I missed a bullet and will check the coolant weekly going forward. Any thoughts on the sludge? Hopefully not the beginnings of HG failure. Motor runs very strong, quiet and smooth. Here are the pics. They made me sick when I first saw them.