It's the heat in the top of the piston that determines how much Gap you need, more or less.
So everyone knows if you're building a 9 to 1 compression, basically a lower compression Street motor ...you don't need to be on the big end of the Gap, you can run on the small end and be fine cause youre not going to have as high a heat spikes as you would with 10.5 comp or more so high dynamic/cranking. The octane with the lower compression has a lil room to tolerate the the squeeze..where as if you run it raged edge...the piston top is exposed to leanness, occasional inaudable ping. If you had an egt you could see it.
