Do not...repeat... DO NOT get the BKR7EIX-11. They are gapped to .44.
I'm only mentioning this because all the Discount/Advanced Autoparts, and any other hardware/auto store has the wrong ones listed in their system and will inadvertantly sell you the wrong ones. With the issues your having you don't need to add more problems by having incorectly gapped plugs.
Good luck and let us know how it goes.