I decided to check the timing, using my maintenance manual instructions. (I don't have tools for compresion testing.) I reset the manual advance, then hand cranked the engine until the pointer and flywheel mark lined up. But the rotor pointed to the #3 wire, not the #1. So I'm thinking the timing is way off or the spark plug wires are in the wrong distrib cap holes. Looking at the engine from the passenger side, my firing order is 1-5-3-6-2-4 (It's a 228 in a '53 GMC.) The order on the distrib cap, from the 12 o'clock position, was 6-1-2-3-4-5. I pulled the plugs and stuck them in 4-5-6-1-2-3. In other words I rotated all plugs clockwise 2 holes. (I hope that makes sense.) I turned the distrib housing until the points were opened and tightened things up.
With a fire extinguisher beside me, I cranked her over. I did get some firing, and some smoke blowing out the carb. A complete, accurate tune-up is a little beyond me, so I am thinking of having some old-timers at a local garage look it over. What do you think?

1953 GMC half-ton