I have a 312 that's bored .040 over, Blue thunder intake, mild cam from John Mummert, and Pertronix Ignitor (the original, not the II or III).  I just recently installed the Pertronix 40k volt, 1.5 ohm "Flame Thrower" coil and I'm wondering if I should continue running Autolite spark plugs gapped at .035 as I did with my old 20k volt coil, or should I try widening the gap to about .040 now that I've doubled the coil voltage?  The car is running good, but if there's room for improvement in power, gas mileage, idle/start under hot conditions, etc., I'd like to give it a try.  I'd be interested in hearing from others who have this combination and have experimented with plugs and gap sizes.  Thank you, Ron.