Finally got to flushing out the left tank on Fluffy [my 818], still have to do the right side, but that can wait for another day.
Before I cleaned the tank out, I looked down inside of it and the older diesel was so black that I could not see my LED flashlight when I submerged it about 1".
Somehow, someway this truck ran on that black swamp sludge that resembled diesel fuel for a nice 300 miles round trip without any major issues. I'm sure the filters were not as amused as I am, but they will be changed out later.
After flushing the tank, ran her around the block and down the street to give her some more clean go-go juice. The idle is smoother and the throttle response is much better.
Amazing what good clean fuel can do for an engine. And we all know a clean engine is a happy engine.