Rumblefish, can you give me a plug number? I tried a stock plug but I can't get the hex in the hole, but a tapered seat plug will fit but I don't know the number to use.
A stock plug....that the hex can't fit in the hole? Stock head to the stock engine? What year engine and head?
Tapered plug? What plug?
Below are OE numbers for a couple of engines. HIgher the number, the warmer the plug.
R = resitor
N = size or reach
number = heat range
Not sure of the Y or C
RN12YC are the Chamions. Thats the superseded number I believe.
Stock Champs for a 340, 68 - 72, N9Y colder plug
(Note the years covered for the 340.. Theres no worry about emmisions and the engines comp. ratio is higher than the '73 + engines. Clue????????)
1973 - 340, N12Y, a warmer plug.
early 360's, N 12 or 13 Y
'67 - 318
J14Y 3/8 reach
N14Y 3/4 reach
Both above are warmer but notice the different length or reach.
Edelbrock uses a smaller hex on there heads. As so recomended by them.
Sorry, I'm a little lost and do not feel like I answered the question properly or enuff. I hope I provided enuff of old history here to give a decent part man a clue to look for.
I can not remember the Edelbrock head recomended plug number, but I have a feeling that the RN12YC is it. It has a reduced hex.
I'd start with the 12 heat range. Your probably good there.
