[GlobeWarmer]

School me.

Relative to this NA 426 I'm planning on, I'm planning on 1-step colder plugs. Then I was told "no, no man, go with 2-step colder, allows for more timing when tuning."

Thoughts on this? I don't really want to have to pull the plugs to replace them right after installing them because they are fouling or something.

And on each heat range, what's the recommended gap? Still .040?

 

[ekaz]

Rule of thumb is 1 step colder for each 100 hp your adding. I went from 425hp (stock engine) to 625 on my 426, so I have 2 step colder plugs and zero issues.

 

[GlobeWarmer]

Hmmm...and you had 11:1 426 too...many thanks man.