Not sure if anyone is interested, but there is a set of AC-45XL on Ebay for sale right now that list this for it's application:
Chrysler - 1954 - V8 - All
Chrysler - 1955 - V8 - All (except Windsor)
Nash Metropolitan - 1954 1955 1956 1957 1958 1959 - All
Packard - Late 1955 - 320 V8 - All Spark Plugs
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