Found this little tidbit;
OPENING THE SPARK PLUG GAP:
For as long as engine builders and racers have been tuning engines there has been talk of enlarged or modified spark plug gaps. The theory is that by opening the gap that you increase the spark kernel, thus improving flame propagation (complete burn across the entire area of the piston), and increasing performance output of the engine. Well, I can say that it does work, but I can also say that it does not work. The explanation for this is that on some applications you will see gains, on others you won't. In some cases you may actually lose performance by opening the plug gap.
On weaker, or stock ignitions, opening the gap puts added strain on the other ignition components in the system. On race ignition systems you are already taking advantage of the output of the ignition box, extended spark duration, and more efficient energy transfer. The only honest way to discuss modifying the plug gap is to experiment on your individual application. You'll either see a benefit, or you won't. Spark plugs gaps are a trial and error type of science when you deviate from the manufacturer recommended settings. If you increase the gap at 0.001" - 0.002" steps and you get to a point where you lose power you will need to close the gap up 0.002"-0.003" to be at the optimum gap. This is what you need to think about:
The ignition coil may not have enough stored energy to fire, or in the least case, not enough energy by the time it gets to the plug to be able to jump the gap.
Plug wire leads will break down at a faster rate due to the added resistance as the spark tries to reach ground.
Rotor, distributor cap, points/condenser (if using an antiquated breaker point distributor), and the center carbon in the distributor cap will show early failures.
The chance of spark scatter in the distributor cap increases.
All of this occurs because the greater the gap, the higher the voltage requirement necessary to get through the components to jump the gap. The harder these components have to work, the shorter their life span. As a side note, on aftermarket, and high performance rotors the tip is a bit longer to control spark scatter on higher output ignitions.
