[edwhite7]

I have a 427 medium riser and have a dual quad setup. The carb size is related to whether the manifold is single or dual plane. A dual plane needs a bigger carb than a single plane. My current tunnel wedge (single plane) with two 450's works better than my Ford dual quad dual plane with two 650's. Both run a little rich at idle but the dual 450's have much better throttle response.