Jerry, this is good stuff! To the best of our knowledge, this is the first time the engine has been overhauled; the sludge throughout was attrocious, as was the wear. I do know the head was cleaned and surfaced back in the early 2000's, after the truck sat abandoned in an orchard for many, many years. The rocker arm assys are currently out being rebuilt, but looking at pictures I took during disassembly, it does have a single oil lined plumbed in the center.
