Swap your PV out for a plug. Check your wet fuel-level. Look down at all your butterflies front and rear; the valves should not have fuel on them while idling. Close your mixture screws up to 1/2 turn and do not change the speed-screw setting, nor the timing.
Go to the back of the car and put your hands over the tailpipes, in a modest effort to keep them closed. You should NOT feel any tendency for the pipes to suck your hands onto them; only pressure. Your pipes must be leakproof for this test to work.
Now check for too rich out the tailpipe.
Not smoking? pressure test your extracted PV, and replace if the diaphragm is perforated.
Still rich? IDK, you are running a PCV right? If not, get-R-done.
Still smoking black? Ima guessing your ignition is weak, or your plugs are beyond saving.
After that IDK
With the PV plug in there, you will not get much over 1/4 throttle, to perhaps 10" of vacuum in second gear. If you want to you can do some power roll-ons with a vacuum gauge on the windshield. Get her up to ~2200 in second gear and let the speed stabilize. Then gently waffle the gas pedal down from the stable cruise vacuum, whatever it is, to between 12 " vacuum and 8" vacuum. Somewhere in that range the AFR is gonna go lean, and the engine will complain about it. Keep waffling the peddle gently until you find the lowest vacuum that the engine is still happy with. And that will be the PV to install. I'll go out on a limb and say you need a 10.5 ,lol
That's all I got
