The answer to this question is related to the discussion about runner volume between cylinder heads –you’re going to want to look for velocity for low rpm torque, and flow for high rpm horsepower. Note that most carbureted performance intake manifolds are divided into two basic categories –dual plane and single plane.

For the most part, dual plane manifolds tend to be better for low and midrange torque and horsepower, and single plane manifolds (sometimes called open plenum intake manifolds) tend to emphasize mid and upper-rpm horsepower. Which is better depends on your application –but in general, dual plane manifolds are better for street use, and single plane manifolds are superior for track use. When in doubt, check with your intake manifold’s manufacturer for specific powerband and application rating information.

EFI manifolds will vary in application based on individual design characteristics, with improved midrange and top end horsepower being common advantages of aftermarket EFI intakes, and low and midrange torque being a strong point of OEM EFI intakes.