71 340 running bad

Swap on one of your known good Edelbrock 1406 carbs, and listen to it Perrrrrr.....

Process of Elimination

Will answer a lot of questions right quick.

View attachment 1716116946

Edit:
See you already tried a second carb....

☆☆☆☆☆
Thats what I did when I discovered my Thermoquad was leaking raw fuel into my intake...