Found this video which illustrates what everything under the timing cover looks like, including the nozzle (squirter he calls it). I don't know if this view makes me feel better or worse given some of the things that he talks about that could produce a leak. The engine was completely rebuilt long before I acquired the truck, but it hadn't been run very much (if at all) since the rebuild.
https://www.youtube.com/watch?v=p2RAiCRke1I