Holley 300-137 - Intake Manifold, Ls1 Efi Single-Plane

Single Plane EFI LS Intake Manifold. All GM LS Gen III or IV engines equipped with LS1/LS2/LS6 style cathedral port cylinder heads. Single Plane EFI LS Intake Manifold. All GM LS Gen III or IV engines equipped with LS1/LS2/LS6 style cathedral port cylinder heads. Features: • 2500-7000 RPM power band • 4150 Square bore flange • Optimized runner layout and constant cross sectional area - broad torque curve, best vehicle performance from 2500-7000 RPM • Minimum carb flange height - fit in vehicles with minimum hood modifications • Cast aluminum construction - great manifold for centrifugal blower, turbocharged or NOS power adder applications • Efficient casting design - lightweight, consistent wall thicknesses, improved casting quality • Weight - 11.5 lbs. • Height (front) - 5.417" to the lifter valley cover flange at the engine block front flange • Port size - 2.50" height x 1.15" wide • Includes Viton® O-ring intake to cylinder head gaskets - Viton® is a registered trademark of DuPont Performance Elastomers • Kit does not work with factory fuel rails and requires the use of Holley Fuel Rail Kit P/N 534-219