My '03 has 233K on it. All original drivetrain components(down to the water pump!) I did rebuild the alt. a couple of months ago though, (it was working fine, just wanted to do a little PM). No leaks and burns nothing but gasoline. Super clean, reliable truck!! I change all the fluids regularly with sythetic wherever possible.
Question...I've never flushed the cooling system. I'm leary of flushing something loose with this many miles on it, causing a leak or plugging up the htr. core or radiator. Any suggestions on this topic?