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1954 Packard Clipper Super L8 165hp...thoroughly cleaned the distributor and points and reset gap on points at high lobe of distributor cam. Cleaned and reset plug gap. Set proper timing with timing light after setting point gap. Set carburetor and engine idle speed with engine warm. Car runs beautifully when just started in the morning...smooth and quiet no vibration. But, when I drive it a short distance (mile or two) and come to a stop sign or traffic light at idle, the idle is rough and stumbly and the engine vibrates the car. If I shut the engine at that point and immediately restart it, it seems to run mostly smooth again, until I drive it a short distance more and the rough idle begins again. With the ignition issues seemingly sorted out, I am beginning to think I have a carburetor issue.
Appreciate any suggestions you may have...thanks again!

Check the carburetor fuel bowl vent.

Have you checked the fuel tank to make sure you dont have debris floating around? Suction on the pickup sucks up the debris, and starves the motor of fuel. Then the motor dies. The suction goes away and the debris floats away from the pickup, and the engine will then restart. Rinse and repeat.

Also, make sure the fuel tank is venting properly and not building up a vacuum. Had that same issue on a bike, was a clogged gas cap vent. Simple test, try it with the gas cap off. Doubt you'll get a check engine light like a newer car

I am pretty sure it's not debris in the gas tank..the tank was overhauled when the car was partially restored by previous owner. Removed gas cap with engine running that did not seem to make a difference in the rough idle. I noticed that the screws were loose on my Carter Climatic Control knob that houses the thermally controlled tension spring, so I tightened those up to lock the black plastic control knob in place after adjusting the tension for smooth cold start. After warming the engine to normal operating temp with choke wide open, I looked down the throat of the carburetor and accelerated the engine a bit. Looks like the driver's side (high speed?) large diameter jet was dribbling fuel but the passenger side jet did not start to dispense fuel until much greater acceleration...pardon my ignorance..is this normal? Also, should the fuel dribble and gush out of the jet or be a spray of fuel? Trying to analyze what I think is a carb problem. Thanks again.

That is EXACTLY what the WGD carb on mine did, one side dribbling slightly more. Also, make sure to check it at idle...when i had my idle set high it was starting to draw from those mains. I don't have enough experience to say whether or not it's normal.

Mine had the same rough idle, all the time, when warmed up...but NOT on choke when cold. Going through the ignition didn't do much, and no amount of adjusting would fix it. I had the carb professionally rebuilt.

I had a 4bbl manifold lying around, and a line on a 4bbl correct carb for the 327 motor i had transplanted and just got that done the other day. It runs smooth as I've ever seen it now with the 4bbl manifold and carb on, which leads me to believe it was a carb problem after all. It does seem to still suck some gas out of those nozzles at idle, but i haven't adjusted the idle down from 650rpm to 500 or so yet. Good luck with yours.

Also, i bought a spare wgd used carb from ebay for an olds 88 and it ran decent but never idled smooth either, but then again i fixed some ignition issues and never tried it again after that, maybe the spare carb was good? It was nice to have another one to hot swap on and test with, but in the end i just wanted done with the problem and i had to remove the manifolds to fix an exhaust leak anyways, so i just did the upgrade to be done with it, to maybe get better fuel economy, and to get a little more oomph on the highway.

Yes, I think I will have the 2bbl carb rebuilt and see where that takes me. Does not seem to be too expensive a proposition. Once that's done it will help me narrow things down considerably. Thanks for your help.