Spark plug advice???

[tsteiner61]

Just wanted your two cents on this.

In going from a stock 360 (8.5 nom. CR) to a 408 stroker with KB pistons and a 9.5 CR, would you suggest going a step colder with plugs or just run stock. The car will be daily driven, mostly city street driving, some highway.

Thanks in advance.

[Ausydad]

Hey Tsteiner,
It's been recommended to me to run AP63's with a .040 gap. Hope it helps.....

[RALPH]

i would stick with the stock plugs. champ RN 12YC should be good. don't let the part store guy give you the 14YC's i think those are too hot. i wouldn't waste monet on the splitfires or accell plugs cause i played with them at the track and had absolutely no gain whatsoever

[BrianU]

In my 340, I run either RC9YC's or NGK GR5's both @ .037"