To expound a little further, here is Summit Racing and Offenhauser's description.
"Offenhauser's 360 Degree Equa-Flow Single Quad High-Rise intake manifolds feature a 360 degree design for full-capacity operation. This combination of unrestricted fuel-air flow and a divided plenum means no flat spots throughout the entire rpm range. What does all this mean? The equal fuel flow to each cylinder increases horsepower and torque, while evening-out individual cylinder temperatures. Power bands start as low as 1,800 rpm with a small carb and climb all the way to 8,800 rpm with a big one."
