767Jockey Since KCR is selling the heads and camshaft to you, It would be a little foolish to not go with his carb choice. I don't know what manifold you are running but I would send it out to Joe Craine and let him balance the ports up. On some manifolds there is a 10-30CFM differents between ports. I would also give him the size of the ports. You want the intake ports to be just a hair smaller than the head ports. This gives a smooth transition. Rick L. There is a formula that works pretty good for getting the right carb size. I would being looking at something in a 650- 780 for the street. The dyno work with the A/F readings are going to tell you what the motor wants. Carbs are like camshafts, bigger is not always better,
It's just BIGGER.
Rick L.