Here’s a picture of a modified two barrel manifold that was used in a circle track application where the use of two barrel carbs was mandated. The slot in the manifold has been removed which will ultimately hurt lowend torque numbers but this manifold was the points champion in its class the last year it ran. This particular engine used a 500 cfm 2 barrel Holley with an overbored 312 sporting domed pistons and heavily angle milled “G” heads. For higher lowend torque numbers, the smaller and properly tuned 2V carb will edge out the larger carb but HP numbers will be better with the larger carb.