1963 Spark Plugs Resistor or Nonresistor

[Jeff C.]

Were the factory spark plugs AC-44 or AC-44R?
Thanks

[Jeff C.]

Re: 1963 Spark Plugs Resistor or Nonresistor

Found my answer.

[Duke W.]

Re: 1963 Spark Plugs Resistor or Nonresistor

Resistor plugs did not become production standard until 1969. Non-resistor plugs are no longer offered by "AC", and they no longer offer heat range 4, but heat range 5 is more resistant to fouling than 4, which is why I ran AC 45 back in the day, but today they are only available as AC R45 resistor type.

Beware, the current AC catalog calls out heat range three for most applications, which is way too cold for normal road driving.

Non-resistor equivalents to the old AC 45 are offered by NGK and Denso, B4 and T14-U, respectively.

Duke

[William F.]

Re: 1963 Spark Plugs Resistor or Nonresistor

Duke,
Do NGK and Denso still make the nonresistor plugs you mentioned as AC 45 equivalents?

[Duke W.]

Re: 1963 Spark Plugs Resistor or Nonresistor

I haven't checked in the last week or so, but I expect they are still available, though probably not commonly stocked at NGK retailers.

Duke