Charles - more info (maybe
). I have a huge Autolite book that goes through 1968. The DD-236 vacuum advance is listed for several applications, but the most common is '68 302 4-barrel w/IMCO (Mustang, Comet, Cougar). There are a couple of others - truck w/390 and Bronco w/289. The odd thing is that I also have a NOS DD-236 and mine is marked A12, whereas yours is marked B12. Confusing.
BTW, the correct CJ 4-speed vacuum advance (with the HP6) is DD-239.