Browne with hei it is possible to set the gap as high a .050 however there will be no gain! As the mixture in a carbed engine is rich enough to set the gap to .030 and still light the mixture with a spark..
One must think about it a bit. The spark ignites the mixture and in a nanno second the explosion leaves the vicinity of the plug if the spark continues it is to no avail as the mixture in the area is already on fire and unlightable.
The mixture nor the cylinder/piston/valves knows any difference in which spark started the explosion. Nothing will be cleaner or faster or anything else.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />