just wondering what plugs everyone is running in the little 300. I have R43S a/c plugs. but Ive been told that it should be R43FS anyone know the differance. I will also be changine over to eletronic ignition over the winter.any suggestions Im all ears Thanks Tim.
You should only run the R44FFS in the '64 aluminum heads--that is what they came with. The other plugs don't have as long a threaded section and about 1/4" of the threads on the inside of the plug hole will be exposed in the cylinder, plus the plug is resessed up in the head. Only problem is they are kind of hard to find since they only fit the 215 and 300 Buick Aluminum heads. If you have the Cast iron 300 heads, use a R43, R44 or R45S plug
Thanks for the replies.Brain you brought up a point that had me concered also the lenght of the thread and also were the spark plug was in relastion to the cumbustion chamber. Im running a Champion plug that seems to be the right plug with a much longer thread design.
