Spark Plug Confusion

You know, there ARE times when you don't always have to be a smart aleck.

Yeah, right, I'm so sure. :lol:

I ask mainly because the cylinder head on Vixen's engine has been heavily

So you'd want to do a physical check, accounting for your piston deck height and the head mill, but it's kind of academic because if your compression is way higher than stock, you will probably want a colder-than-stock spark plug, which would eliminate the ZFR5N from consideration.

But they work great in stock and nearish-stock motors, which is kind of the kind this here thread is about.