LS3 Rectangle Port Carburettor Hi Rise Single Plane EFI Intake Manifold

Transform your GM LS engine with Aeroflow Performance’s LS3 Rectangle Port Carburettor Hi Rise Race Single-Plane EFI Intake Manifold. This Hi Rise, single-plane design is engineered to keep air and fuel flowing evenly, delivering peak performance and efficiency for high RPM applications. The 4150-square-bore carburettor pad supports aftermarket square-bore throttle bodies or adapter plates, making it a versatile EFI upgrade for LS3 rectangle-port heads.

Designed for GM LS Gen III and IV engines equipped with LS3 rectangle port cylinder heads, this EFI-ready manifold is a direct-fit upgrade that complements factory electronics while expanding fueling options. The natural cast finish showcases rugged durability, while the high-rise, single-plane configuration prioritizes mid- to high-RPM power.

Key specifications

• Square bore carburettor pad (4150 flange) for a 4-barrel throttle body
• Overall height (carb pad to bottom of manifold): 172 mm (bonnet clearance should be checked)
• Port size: 1.08" x 2.45"
• Intake manifold flat style gasket (must use Fel Pro 1222-2 or 1222-3)
• 5/16-18" carburettor studs (x4)
• 4 x M6 x 1.00 mm mounting holes for fuel rails

What's included

• Intake Manifold: 10 x M6 x 1.00 mm hex screws (50 mm UHL) and 10 x M6 flat washers

Fuel Rail Kit and hardware

• 2 x Fuel Rails (-8ORB)
• 1 x -8AN crossover 100 series braided line and two 90 degree non full flow taper fittings
• 3 x -8AN to -8ORB fittings
• 1 x -8ORB hex port plug
• 4 x mounting brackets
• 6 x M6 x 1.00 mm socket cap screws (25 mm UHL)
• 6 x M6 x 1.00 mm hex screws (12 mm UHL)
• 4 x M6 nuts

EFI compatibility and installation notes

EFI applications only. This manifold is designed to accept aftermarket 4150 square-bore throttle bodies or adapter plates for retrofit applications. It does not work with factory OEM fuel rails and requires the Aeroflow Fuel Rail Kit AF6999-5000.

Requires 14 mm short (33.60 mm) fuel injectors (sold separately).

RPM operating range: 2,500 to 7,000.

For non-EFI applications, AF6040-6005 is recommended.