massive reconfiguration time again.

Some of me wants to just put the old carbs back on the way they were set up and check this O2 sensor.. I bought some off cheap brand to go on my wideband and it's all over the place. But when it does seem to be reading correctly it is reading a point or two richer than what I'm used to seeing.. and I wonder about the set or the dark color on the plug outer ring that's just being rich?.