I pulled this motor when I bought the convertible and installed a new engine. Decided to pull this apart and it looks like the timing chain guide came apart and locked up the cam when trying to start it. From what I can tell the previous owner stopped running it when they got the death rattle. (they are friends of mine).

It doesn't look like the valves are bent or the block is bad, so this one is rebuildable. I was going to take it for scrap...good thing I didn't.