Non-resistor plugs for big block

[Patrick B.]

Is there a non-resistor plug in the equivalent of the AC 45 heat range for a 69 big block with aluminum heads? It needs full threads for the aluminum heads.

[Joe L.]

Re: Non-resistor plugs for big block

Is there a non-resistor plug in the equivalent of the AC 45 heat range for a 69 big block with aluminum heads? It needs full threads for the aluminum heads.

Patrick-----


Yes, AC 45XL, aka GM #5569737. Long ago discontinued, though.

By the way, all 1969 Corvette applications originally used resistor type plugs.

[Patrick B.]

Re: Non-resistor plugs for big block

I was looking for the equivalent of Champion N12YC or N13YC in Denso or other brands that Duke says are non-resistor. I used N9YC and N11YC when I drag raced the car and drove it more regularly than I do now.

[Duke W.]

Re: Non-resistor plugs for big block

Check the Denso, NGK, and other brands of your choice Web sites. All should have cross reference charts that will tell you if they have an equivalent of the out-of-production AC 45XL or 45XLS if you want an extended tip plug, but like Joe said, '69 was the first year that resistor plugs were OE.

Duke

[Joe L.]

Re: Non-resistor plugs for big block

Check the Denso, NGK, and other brands of your choice Web sites. All should have cross reference charts that will tell you if they have an equivalent of the out-of-production AC 45XL or 45XLS if you want an extended tip plug, but like Joe said, '69 was the first year that resistor plugs were OE.

Duke

Duke------


1969 Corvettes did use resistor plugs for the "first time in a long while". However, it was not the very first use of resistor plugs in a Corvette. That goes way back to the very first 1953 Corvette through 1955. The plug for those was the AC 43-5R, aka GM #5569889.