Need help tuning Quickfuel carb

The wires are routed as far away as they can be and in their own individual looms.
Carburetor power valve is an 8.5hg, idles with 20hg of vacuum in park and Idles with 15hg of vacuum in gear.
I just checked for vacuum leaks again tonight and I can’t find any, I’ve sprayed carb cleaner along the sides of the intake and listened for a change in idle, no change at all.
Sprayed around the carburetor, no change in idle.
The plugs in cylinder 6 and cylinder 8 are never oil fouled, they are carbon fouled, too much fuel, they have a dry sooty black substance on them like the inside of a chimney would have.
Like I said I had spoke to a guy at AED performance carburetors and gave him all the information and he is blaming it on the 4 hole carburetor spacer causing a fuel distribution issue and suggested trying an open spacer.
I can get an open spacer for 20 bucks at my local part store so even though I am skeptical of it being the problem I’m going to give it a shot and see what happens.
I’m also going to wait till it’s pitch black out and fire it up and have my wife bring up the rpm’s to where it starts missing and watch for spark scatter around the plugs, because this is about the 3rd time I’ve been told the Taylor wires suck and leak spark around the boots causing missfires.