Actually coil saturation time (dwell) is determined by the ignition module or by points closed time on a points ignition.
That said, there is also something to the idea that a spark that jumps a gap has more inertia.
This is why a fouled plug can sometimes be made to fire by pulling the plug wire back and making the spark jump a bigger gap on it's way to the plug.
I use this method to help determine if a missing cylinder is a bad or fouled plug or possibly a valve or compression problem.
If you make the spark jump farther to the plug and that cylinder doesn't change any, there is probably a bigger or different problem.
It's not a tell all, but just a possible clue.
