Someone may have your same combination and have the perfect answer. In the mean time, I would recommend starting with the OEM plug and see how it runs. If it tends to foul or carbon up prematurely, move to a higher number for a “hotter” plug to keep the plug clean. If the plugs run for a while and come out chalk white, or you get detonation at normal timing settings, then move to a lower number plug, so it runs cooler.