NGK spark plug № ZFR5N (stock № 3459) is going to be a better pick than the standard plugs, without costing more. Quality is very much better than what Champion or Autolite will sell you, and this particular plug has extended/projected electrodes that move the spark away from the quenchout zone, for more complete combustion. There's nothing such as a magic spark plug, but these will gain you a little bit better driveability and fuel economy.
Whichever plugs you wind up choosing, gap them at 0.035" and make sure to remove their metal ring washers before installing them.
