I can't offer an opinion without knowing what your build is other than to say anything except
Champion.Autolite,AC,NGK will serve you well as long as the plug's heat range matches the needs off your engines build and operation.
Probably!I use the 45's and pound the crap out of it, is that wrong?
Not every body is as good at tuning as you are James.James if it ain’t broke don’t fix it!