The AFR heads I have mixed feelings about. Im sure the flow great but the componets they come with are garbage. The worst part is that the aluminum is so soft ive pulled threads on three header bolts already and cross threaded another. They use a 3/4 inch bolt instead of an inch. Would be so much better if they used steel thread inserts like edelbrock. If I had to do it again I would not go with AFR

 

Idle mixture won't do it. You need to set the idle transfer slot properly. Raw fuel in the combustion causes it a lot of times. .020 on the slot and make up the rest in the back.