While the 250 series race cars were well-known for the beautiful six two-barrel Wber carburetors the normal “street” cars used “only” three two-barrel carburetors and the large “three-in-one” air cleaner assemblies still supplied by F.I.S.P.A. These had satin black-painted tops and bottoms with nickel-plated perforated steel side panels. The “inside plug” engines and the outside plug engines used this tag and a few other details until the GTE production began. They had the two-ear wing nuts on the air cleaner tops, silver-painted timing chain covers and these metal air cleaner tags. I have seen these three details on cars as late as #2039 and I think that the change to the F.I.S.P.A decals, black wrinkle timing chain covers and three-ear wing nuts was made about that time. “inside plug” air cleaner tag with 70mm rivet spacing.