Spark plugs for 440

[7dcuda]

Looking for recommendations for a good spark plug to use in my street 440.  I have always used Champion RJ12YC but lately have had problems with them fouling....the ones made in Mexico.

[Chryco Psycho]

That is what I have always used , maybe the carb can be tuned better ?

[1 Wild R/T]

Assuming something close to a stock 440 Magnum.....NGK 3332
Cam & compression can effect plug choice as can aftermarket cylinder heads...

Lotta people like Champions, Personally I've never had any luck with them, they fouled back in the 70's, they fouled in the 80's & in the 90's...  "Insanity is doing the same thing over & over expecting different results". I quit trying Champions... Been using NGK's for many years with great success....

[Cuda_mark]

I also had issues with Champion fouling on my 512 six pack. I switched to Motorcraft with good luck but agree that you can't go wrong with NGK either.

[Chryco Psycho]

I have never had any luck with NGK , they always fouled faster & quit firing for good , no way they would clean up & start firing again .

[RUNCHARGER]

I've had good luck with NGK's and ACDelco.

[Montclaire]

I used to run Bosch platinums (single electrode) and was very happy with them. They would burn very clean where the Champions would not.

[7dcuda]

Think I'm gonna give NGK a try.

[7E-Bodies]

Gonna be wondering the same soon on my stock 440. Any particular number on the NGK?

[Brads70]

I have never had any luck with NGK , they always fouled faster & quit firing for good , no way they would clean up & start firing again .

I've had the same experience but maybe I have the wrong heat range? Going to try Campions next as I stock them in my service van ..... same plug used in lawn tractors lol

[7dcuda]

Gonna be wondering the same soon on my stock 440. Any particular number on the NGK?

Im trying the NGK 3332 (XR5) suggested above.  It's a copper core cross reference for the Champion RJ12YC.....just installed them, so far so good.....time will tell.

[Racer57]

Looking for recommendations for a good spark plug to use in my street 440.  I have always used Champion RJ12YC but lately have had problems with them fouling....the ones made in Mexico.

You mean like this ?  Same plug as yours but in my 383. Had a flutter sound and like an idiot I thought it was a bad muffler and bought new. Still did it and found this. All other plugs looked normal except this one that reeks of gas.

[dodj]

I've had good and bad experiences with both. NGKs in my outboard gave me a lot of grief. Switched to champions and was fine. Probably just needed a different heart range ngk. I've also had a 12yc in the 440 only last a month.
Last set of champions have been in my car for 5 years now. No issue.
IMO, they will both work fine, and,  they can both fail.
And fouling isn't necessarily a plug problem.

[Skdmark]

Based on a recommendation, I'm going to give Autolite AP66 a try in my 318 when I install the Holley Sniper.
Worst case I go back to Champions or NGK (have used both before in my 383).

[docmel]

That one plug shows a possible causes of:

Just a spark plug that is bad
Valves on that cylinder need adjustment
Bad spark plug wire  (Or poor connection at spark plug or distributor)
Poor spark plug gap, or way off heat range from the others
Distro cap needs replacing due to carbon buildup/arcing