AC Spark plugs

[Benjamin C.]

What are the correct AC plugs for a 1967 427/435?

[Jeffrey S.]

Re: AC Spark plugs

When you say "correct" I assume you mean what was supplied from the factory. These were AC43N's with 4 thin green bands. For anything other than Bloomington judging or hard usage, they are too cold. If you want an "original style" plug (a non resistor AC plug)for light use, I would use a 44N or even a 45N.
Jeff

[Jeffrey S.]

Re: AC Spark plugs

When you say "correct" I assume you mean what was supplied from the factory. These were AC43N's with 4 thin green bands. For anything other than Bloomington judging or hard usage, they are too cold. If you want an "original style" plug (a non resistor AC plug)for light use, I would use a 44N or even a 45N.
Jeff

[Clem Z.]

Re: AC Spark plugs

i would use a R-45XLS which is a extended tip plug that will stay "cleaner" longer

[Clem Z.]

Re: AC Spark plugs

i would use a R-45XLS which is a extended tip plug that will stay "cleaner" longer

[Richard P.]

Re: AC Spark plugs

What about plugs for a 1965 327/365 all original? 1964 327/300 ?

[Richard P.]

Re: AC Spark plugs

What about plugs for a 1965 327/365 all original? 1964 327/300 ?

[Jim T.]

Re: AC Spark plugs

I have always used Champion plugs in my 327/300, 350/300, and 327/350. I perfer the extented tip of the Champions for my daily drivers.

[Jim T.]

Re: AC Spark plugs

I have always used Champion plugs in my 327/300, 350/300, and 327/350. I perfer the extented tip of the Champions for my daily drivers.

[John H.]

Re: AC Spark plugs

Rick -

I run AC R45S plugs in all my small-blocks ('69 Z/28 and '67 300hp Corvette), ran them in my previous '57 270, and many others. 44's gave some fouling issues in town driving, have never fouled a 45S.

[John H.]

Re: AC Spark plugs

Rick -

I run AC R45S plugs in all my small-blocks ('69 Z/28 and '67 300hp Corvette), ran them in my previous '57 270, and many others. 44's gave some fouling issues in town driving, have never fouled a 45S.