To receive a benefit from an ignition mod, such as a "hotter" coil, one needs to make a change to the plug gap. That is to say, increase the gap by several thou.
Run a search on this topic, as I've addressed this change, before.
NOTE: Wider plug gaps help burn the richer mixture, or, put another way, wider gaps (and greater energy to get the spark to reliably jump that bigger gap) can cause a well-jetted motor to run a little lean.
