The Stovebolt Site Forums The Shop Area Engine Shop 216 Intake / Exhaust Manifolds on a 235, help?

I'm interested to what extent the idle mixture screw can help with the soot. Seems to be worse after replacing the Rochester B with a Carter on my 216, as evidenced by the black spot on the garage floor. All parts stock for the 216 in my case but since it's closely related to Dusty's question will tag along here. To be honest I've never even touched the Carter's mixture screw, so probably should do that. Runs great with it otherwise though.