Plug gap and type with Flamethrower coil?

[Cdaniel]

For a little fuel mileage more than anything, looking for best plug match to a 289 with Pertronix ignitor/coil setup.

 

[65fastback2+2]

if i remember right spec is .32 to .37, since you are getting a better spark than stock, you can go prolly .39. I just set mine to max spec, .37

 

[geegee]

Here's what Pertronix says (www.pertronix.com). Look under "Support", "Troubleshooting":

What should I gap the spark plugs to?

The Ignitor has no set specification in which the spark plugs should be gaped at. Every engine responds differently to spark plug setting. In most cases increasing the factory recommended gap by .005 improves the engine performance.