Trouble running when first starting
Sounds like the choke to me. Insure the "choke pull-off" or "unloader" works. It is a vacuum pot. that pops the choke open slightly the second the engine fires. The choke must be tight while cranking. If it doesn't pop open, it will run rich. The rubber diaphram usually fails, especially if you spray carb cleaner near it. Simple to test and replace.
I had a Holley 1920 that always idled lean once the engine warmed up. Actually ~3 rebuilt ones over decades. Finally got a good one that ran super smooth. Make sure the 2 air bleeds at the top of the throat are open. You can find a free manual on-line that tells exactly how to test & fix.