Running rich....To big of a carb or?

Your problems are what i said they are.
The power valve will open at idle if it go's below 9.5 on a vacuum gauge.
Your 77 primary jets will turn into about a 85 jets under acceleration when the power valve fully opens.

Just change your jets to a 71 and get a 3.5 power valve,

Look up holley video on u tube.

You want the main primary jets to match the rear secondary jets when under acceleration.