318 poly w/ carter AFB rough running especially idle and off-idle.

Cool. Just remember to close it slowly enough as not to stall the engine. You're looking to see if closing it some will make it run smoother. If it does, there's a vacuum leak somewhere. You can zoom in on it with a spray bottle of water. A lot of people recommend carburetor cleaner sprayed around the carburetor base. I cannot, as I have seen a fire started that way. Water will show it up just as well and is perfectly safe. Good luck!