You're using ported vacuum, unplug your vacuum advance and plug the gauge in there.
https://documents.holley.com/199r11202.pdf
https://documents.holley.com/199r10014rev1.pdf

The PV (power valve/enrichment valve), if its diaphragm and gasket are sealing (verified by installing new one), will not add fuel to the idle circuit even if opened as it feeds fuel through the venturi boosters and operates off venturi vacuum, manifold vacuum only controls when it opens.

The carb is idling way too rich, the idle circuit is not fed by the jets in this carb design. While jetting is absolutely going to need adjustments, IMHO, first up should be getting the idle circuit under control.

The OP just gave us a clue that he did not buy this carb new or he would know more about it. It is possible the carb has been fiddled with by others and the idle feed restrictor may need changing.
https://www.musclecardiy.com/perform...bration-guide/

JMHO, Once we get the idle/transition circuit under control we can move on to further tuning the carb.