After the car was media blasted, Andrew at Labrecque found a spark plug in the rear trunk area wedged in the body. The spark plug looks brand new, but 1/2 of the spark plug got media blasted.
Here are two pictures of the spark plug:
3 thoughts on this spark plug:
1) It’s a AC R43. With a few searches at the CRG, this appears correct for a 69Z.
2) It says “AC SPARK PLUG FLINT MICH. MADE IN U.S.A.”. I wonder how many spark plugs are still made in the USA.
3) I bought an set of NOS AC R43 spark plugs on EBay. However, the top green stripe is fat. All the green stripes on this spark plug are uniform. I am guessing the fat stripe is a later version. I am not sure if it matters for a judged car. It would be an odd deduction for having a fat green stripe, but it still might be a deduction.