The PCV valve is supposed to close at high vacuum, like at idle.

Opening that port to atmosphere leans down the mixture.

On a normal carb, the starting point for idle mixture adjustment is 1 1/2 turns out from lightly seated.

You are in Salt Lake City, Temple Square is 4320 feet elevation. (On a Holley carb I'd jet down four sizes.) That means your A/F ratio is going to be rich with a sea level carb. You could probably run the Edelbrock electric choke carb as out of the box, as it is set up lean from the factory. If you are setting idle mixture, you will probably go in 1/4 turn or so from the starting point.

Have you set your idle rpm first, then set idle mixture, then reset idle rpm, then reset idle mixture? It has to happen a few times.

If you have to pass emissions, you won't be able to run too much initial advance, at least I haven't been able to.

R.