I think I am near 1/8th on the holes.

Pull carb off and set pri blades at .04 to .02 on exposure and do the same for sec side. Put it back on and see where it idles at when warm. Not just start up and T-stat opens up warm, but running for a while warm. Then adjust back the sec side and then to pri side in equal tweaks.

Manifold choice and cam specs (lobe sep angle) my be the difference here??? Bigger single plane (M1 4500 and 108).

The FV178 seems to be the can of choice for low vac motors. It's a GM piece speced out for their HP solid cammed mills. Not as simple as just walking into box store and grabbing a random PCV off of the display rack.

Mine idles at 1200-1300 free and drops down to 950 or so in gear. Still a little stinky at idle, but I'll live with the choice I made of running a bigger cam on the street.

It costs to be cool and there are some sacrifices that go with the cool factor.