Flutter below 2k rpm

I understand what you guys are saying about 02 gauges and plug reading . I use the gauge as a guide only and understand the pitfalls.

The plugs are darker than the pics show. Kinda like a lightly roasted marshmellow.
But when my eyes are stinging from the fumes and there is a layer of suit in the exhaust tip I can tell you its not running way lean.
Welcome to the world of Hot Rodding
In all the built up cars I have owned over the past 40 some years I cant remember one the did not burn your eyes and gas you out of garage, even when tuned correctly.
Good Luck
I'm out