C2,300 HP ,Sparkplugs Judging Help

[Mark Evans]

Can somebody advise me on the correct spark plugs for my 1967 300 horsepower, automatic. I currently have 10 yr old R44s with the Old style green stripes. I bought replacements from Paragon and they sent me are R45s in the Delco new style. I just went to my local NAPA and he tells me that are R44s are discontinued. His book recommends R43?

Which is the correct AC spark plug for my car?
Is there a point deduction if you use the newer style sparkplug?
Are there any sources for the correct old-style plug?

Mark Evans

[Mike M.]

Re: C2,300 HP ,Sparkplugs Judging Help

old style green stripped ac plugs usually readily available at swap meets(spring Carlisle this weekend). judges don't usually remopve the plug wires to discern the heat range of plug you have installed. mike

[Jim R.]

Re: C2,300 HP ,Sparkplugs Judging Help

R43 is a colder plug used for high rpm use, R45 would be for in town city driving and is a hotter plug you can use either plug but you could possibly fuol out the colder R43.

[Chris Patrick]

Re: C2,300 HP ,Sparkplugs Judging Help

If you plan to drive the car at all, use the R45. The AC 44/R44 is marginally cold and the R43 is way too cold for street driving.

You actually want an AC 44 with four thin green strips which you can only find on eBay and at swap meets to be original. Use an AC 45/R45 if you want to drive and enjoy it.

Take a big wad of cash.