Try adjusting the idle mixture screws with the motor warmed up or hot and adjust them in, one at a time, until it starts to slow down a tiny bit and back it out 1/8 turn richer and then go drive it normally for 10 to 20 miles and pull one plug and post a picture of that plug on here.
The reason I'm asking you to do this is to see if the idle mixture is to rich or the part throttle mixture is to rich scope
When it starts to miss at idle speed it is talking to you, it is either to rich drowning out that cylinder or to lean, maybe a vacuum leak work
Good luck, stick with us, we will help you make it better up
What intake manifold are you running?

Last edited by Cab_Burge; 05/09/20 12:33 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)