The dinky plugs marked AC104 have a modern day Champion equivilent.. called a 842.
Nobody had them in stock.. their Autolite, Motorcraft, and even AC Delco cross refrence numbers to that plug ended up being totally wrong. (read normal sized plugs)
Champions website only lists the one plug for a 1946 Chevrolet Truck.. 10mm, 1/4" reach, 5/8" hex head Stock number 842, Part Number UY6, OE Gap, .037
When I took the plug into the various auto parts stores, the first thing they'd ask is "Whats this out of, a weed wacker?" to which I replied, "No.. my weed wacker plug is bigger than that!"
Anybody else ever seen or heard of these dinky plugs?