I agree with your general comment, but you are 200K miles away from knowing whether it is fine, unless there is some test to determine how the coolant side of your liners are doing.

My wife and I got lucky when we bought her 2000 F350 with the 7.3. Every few years she gets the urge for a new truck, which is understandable given that she hauls trailers full of horses up and down the interstates and cannot afford to break down. Every time the subject comes up, we ask some diesel expert what he thinks and he says, "Don't sell that truck." It has about 145,000 on it now. It has been maintained to the book since new with Motorcraft antifreeze, DCA, coolant flushes, frequent fuel filter changes, and oil changes with Rotella and a quality filter every 3,000 miles. It runs better than new.

Sorry for the hijack.