Troubleshooting stumble at idle in gear

i would pull them and read them anyway just to see if they are black and sooty but your AFR readings wouldn't indicate so...I am thinking it could be a carb stumble ' There is the idle circuit ,then the off idle circuit, the accelerator pump gives "pump shot" to richen it up between idle and part throttle and avoids the off idle stumble. You could check that quick look down the carb and throttle it not running and see if the acellerator pump is squirting nice and strong. I know the carb is rebuilt but it doesnt hurt to check. Youd notice that coming off ide when you just lay into the gas pedal.