I located an NOS Delco Remy distributor cap for the car. The second owner gave it a "tune-up" in the late 1980's and must have tossed the original AC spark plugs and cap. [img]<<GRAEMLIN_URL>>/rolleyes.gif[/img]
The correct cap should have the "Delco Remy Patent 2769047 R" embossed in a circle around the coil terminal. All the modern replacements (including the brand new AC Delco cap I bought), are blank on top. There is also a noticeable difference in the weight of the original caps versus a modern Delco cap. The old ones are glossy, heavy, and thick. The new ones feel almost like ABS plastic and are very flat and cheap looking.