Sounds like you found the issue. That's probably the hardest part. Now unfortunately, you need to throw more money at it! Keep the updates coming!Blizbod, you were right on the money. Went for a drive with out the shaft and it's smooth. One of the u joints is completely froze. Looks like I need a need shaft. Shame on Honda for not making the u joint replaceable.
Backlash on the diff flange was within spec. Quite a lot of play is allowed back there.
Today I finally got some parts. Installed a new rad, pics are in the rad thread, flushed the power steer, flushed the transmission, changed the oil, and installed the new PCV valve.
Good news is that the engine works. Bad news is that it still makes a bit of a whine so I think I need a new power steering pump.
My oil filter had rust bubbles forming. WTF. Probably been on there a while.