Ok so you when to a hotter plug, and they sure look like you when the right way.
I was going to go into a long drawn out opinion on them plugs and your eng.........but the simple fact is that i just don't know.
Maybe you need to attach your smartphone, set it to record your o2 sensor and take a drove. Run threw several sweep of off idle,slow take off from a start, light cruise speeds, full throttle in high gear from say 3000 to 6000 (top rpm) and back.
Tell your camora what you are doing so when you play it back, and see something weird you will know what area of the carb to change......