My Engine was a professionally built 331 stroker with Edelbrock Pefermer RPM heads. The Edelbrock web site states to use Champion RC12YC or equivalent. I looked at a Cross Ref for NGK and came up with BKR5E and BKR5E-11. Does anyone know what the difference of these two are with or without the -11 ?
OK, I found part of the answer on a NGK site the - 11 means gap size in mm. = 1.1 mm or .044 in sae
sounds like quite a large gap but maybe its a fatter spark ?
They come pre gapped at .040
Maybe another Brand is a better choice.