Single Plane Split-Design Race Intake Manifold- GM LS3/L92-4150 Carbureted Single Plane Split-Design Race Intake Manifold Fits All GM LS Gen III or IV Engines Equipped with LS3/L92 Cylinder Heads Holley? A B Height 7. 25 inch (0 carb flange angle) Technical Data: ? Port Size 2. 59 inch Height x 1. 28 inch Wide The Ls Race single plane intake manifold was designed for hi performance racing engine applications, 5. 3 to 6. 2+ liter displacement, and maximum engine speeds of 6000 7000 rpm, depending on the engine combination. This single plane design provides optimal performance across the RPM spectrum while providing maximum performance up to 7000 rpm.