Spark Plugs
 

So of course I have another issue with my build, this one has to do with spark plugs. I bought a set of plugs for the 440 before I redid the heads or anything, Accel 437S, which are header plugs with a 3/8 reach.

I looked at my heads yesterday and realized that the threads are 3/4 so I need a longer reach, Edelbrock recommends Champion RC12YC or similar plugs. The only issue I think I will have is that they will be too long, if I cross them into Accel they recommend 786, which I believe is another long plug.

Does anyone know of a header plug I can get that has the 14mm thread, 3/4" reach, projected tip, gasket (flat) seat, resistor plug?

I think the Accel 416S plug might work, but the applications it lists are for small engines on Toyotas and other similiar cars.

I also found the Accel 414S. The only difference I see is that the heat range for the 414S is cold, and the 416S is stock. Their range is from 1-7 (1 cold, 7 hot) so I should go with the 6?

running a colder plug doesnt hurt anything. it can help insure that detonation wont occur. too cold of a plug will cause carbon build up.to hot of a plug detonation can occur, is you engine mild or built. if its not too hot of an engine 416s would be fine, if its 75-100 more hp that stock id go with 415s if you can find it.

If you didn't see my thread about it, the only stock parts are the block, oil pan, and timing cover.

They don't make a 415s, only 414s or 416s in that series. So the 416s would be the better?

i remeber the thread about the heads. if it was my engine id run the colder plug first. then pull the plug at about 250-500 miles and read them. if they got corbon on them then go to a hotter plug. detonation is very hard on a engine

Ok, that sounds like a good idea.

I was trying to see what was all available but most of the other manufacturers make it difficult to find plugs.

spark plugs
 

My cuz recommends champion j12s. He claims they burn out after a month. I change em about once a year.