plug gapping

[mcvey90]

I know the gap for the stock 302 is like 054 or 056", but when do you have to start thinking about making it larger or smaller. I have a 347 now, and I was just about to put the plugs in her until I thought maybe some of you guys ran a larger or smaller plug gap with more cubic inches.

so is there a rule of thumb, or should you just stick with whats posted under the hood.

thanks for the help

 

[CRASH7772]

It all depends on your ignition. I have a Jacobs Kit on a mostly stock motor running around .63 +or- .02 gap. The motor size doesn't really have anything to do with it. Just noticed your sig.....do you think your tall valve covers would clear a Street Heat intake without a phenolic spacer?