72 duster resto
For what it's worth, I did up a "core" 5.9 for my Dakota starting with something maybe not a bad as yours but not great. The heads were junk, none of the valves would seal so I replaced them with a better set of unknown heads. I did all new bearings, oil pump and timing chain but left the pistons and rings alone along with the cam bearings that I know for a fact needed to be replaced.
My theory on the rings was, I could still see the factory hatch in the bores so I assumed they were ok (yes, I know what "assume" stands for). And I didn't have the time and money to re-ring it.
So far, seems to run good so at least for now I am getting away with it. :D
Never expected it to be a "forever" motor anyways.