Turk,
My 6 yr old grandson does better red crosses than you do.
Maybe you could learn something from him, because you do not seem to learning much of anything else.
And you certainly were not using Plat or Irid plugs in the 70s because they were not available until the 90s.....
Ok smartwad, come up with a single NGK Racing plug number that is available in iridium. They were made for 100,000 life spans not for anything more than that. Have you even put one on a box tester?