'66 350HP CHAMPION PLUG RECOMMENDATION

[Rob A.]

I checked the archives, but didn't find exactly what I was looking for. I like Champion plugs, and would like to install the best ones for combination city and highway driving. Engine is completely stock and unrebuilt. Unless someone has a better recommendation, I guess I'll just find a conversion chart from the recommended AC plugs in my owner's manual to find the corresponding Champion plugs.

[Joe L.]

Re: '66 350HP CHAMPION PLUG RECOMMENDATION

Rob-----

I'd recommend going with a Champion J12YC or an RJ12YC if you want to use a resistor plug. If these don't prove hot enough for your driving situation, then go to a J14YC or RJ14YC. There is no J13 series plug now available.

[Larry L.]

Re: '66 350HP CHAMPION PLUG RECOMMENDATION

I too have a 66 327 350 HP. I gave up on the AC44's, For the last 20 years I have been runing AC43S. The extended tip makes the plug act as a variable heat range plug.
Use an anti seize lube on the threads and torque to spec.
If you use a set of resistor plugs always check the resistor value - it should be be between 4 and 12 K. Anything over 12K will cause you touble after the plugs get a few miles on them.

[Mike McKown]

Re: '66 350HP CHAMPION PLUG RECOMMENDATION

AC 43S is way too cold for street use. AC 44 is too cold for anything but all highway driving. Use AC R45S and you will be happy.