68 340 4-speed distributor
Once upon a time, when there were REAL parts stores with REAL catalogs printed by REAL parts manufactuers, you could look up a distributor (and lots of other components) and find out what it fit as well as the replacement parts numbers. NAPA/ Echlin, Standard Blue Streak, Delco Remy, Autolite, Prestolite, and a few others, Wells, and of course the lovely "Piddle and Diddle Bendix"
If anybody ever tries to sell you these, RUN!!