Originally Posted by Cab_Burge
Champion RN9YC(also RC9YCwill work) or maybe, if you can find them ,one step hotter RN10YCand RC10YC or Autolite #3924 or 3925, those two Autolite plugs have the 5/8 inch hex on them but they will work fine in your motor. I can't remember the proper part # for the standard Autolite 3/4 inch reach resistor spark plugs with the standard 13/16 hex on them blush


That’s too cold for a 10:1 pump gas deal. A champion RC12YC would be the coldest for that and most likely it will need a RC14YC.

Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston