Well, that didn't work out good....
Replaced plugs and wires yesterday. AC Delco parts from Rock Auto. Gapped the plugs to .035... All the old ones looked fine on removal.
Fired the truck up after, and wow does she run terrible. Pinging, backfiring, idles rough, stalls when put in gear.
So, it looks like I did this to myself... Instead of the standard R44T, I went with the Delco Iridium, thinking it'd be better. Guess the ol girl doesn't think so; bone stock '72 with a 350.
Hoping a set of R44T's will get her back purring.