All right, guys ... I followed your good advice. After putting the plugs into the cap in proper order, I turned her over, and lo and behold, I got some decent firing. It almost sounded like it wanted to go! I got three or four fires, then a big "chunk", then three or four more fires and another "chunk". The
"chunk" would momentarily stop the turnover. I'm wondering if I have a bad plug, if timing is off, or ...

I think I can see the light at the end of the tunnel!

1953 GMC half-ton