Mike, the AC45 plug has been discontinued for a long time. It was the factory plug on my '50 Stovebolt, '66 Toronado, and '56 Cadillac.

The in-service replacement is the AC43. I use that plug in all three vehicles and have no problems whatsoever.

There are a lot of AC45s for sale on ebay at around $10 each

https://www.ebay.com/sch/i.html?_fr...13&_nkw=ac45+spark+plug&_sacat=0

Last edited by Otto Skorzeny; 06/28/2022 5:09 PM.
1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)