LS1 Cathedral Port Carburettor Street Single Plane EFI Int Manifold Black

GM LS Cathedral Port Carburettor Street Single Plane EFI Intake Manifold, Black Finish. Engineered for GM LS1/LS2 cathedral-port engines with EFI, this low-rise, single-plane intake optimizes air and fuel delivery across the RPM range for street and performance applications.

• Fits GM LS1/LS2 Cathedral Port Engines with EFI (non-EFI uses require AF6040-5000).
• Single Plane configuration with a low-rise design for enhanced throttle response and peak power in the 2500–7000 RPM range.
• Carburettor pad: square bore 4150 flange for aftermarket 4150-style throttle bodies or adapter plates.
• Port size: 0.95" x 2.45".
• Overall height from carb pad to bottom of manifold: 122mm (check bonnet clearance).
• Gasket O-Ring: AF6233-5002 included.
• Carburettor studs: 5/16-18" x4.
• Port (NPT): 3/8" NPT port x1.
• Mounting holes: 6 x 5/16-18".
• RPM operating range: 2500–7000.

Includes and kit details

• Intake Manifold includes: 8 x Intake Manifold O-Ring Gaskets (AF6233-5002), 4 x M6 x 1.00mm screws (80mm overall height), 6 x M6 x 1.00mm screws (50mm height), 10 x M6 washers, 1 x 3/8" NPT steel port plug.
• Fuel Rail Kit includes: 2 x -8ORB fuel rails, -8AN crossover braided line with two 90-degree fittings, 3 x -8AN to -8ORB fittings, 1 x -8ORB hex port plug, 6 x long mounting brackets, 6 x short mounting brackets, 6 x 5/16-18" hex screws (18.5mm UH L), 6 x 5/16-18" hex screws (12mm UH L), 4 x M6 nuts.
• Note: This intake does not work with factory OEM fuel rails and requires Aeroflow Fuel Rail Kit AF6999-5000 (included with this package).
• Injector compatibility: Requires 14mm short injectors (33.60mm) or 3/4" length injectors (48.65mm) (sold separately).
• Purpose-built for retro-fit: Convert your GM LS engine to a 4150-style throttle body atop the engine for EFI-friendly high-flow performance.

Why this manifold stands out

• Dedicated EFI compatibility with LS Gen III/IV cathedral-port cylinder heads, delivering consistent air-fuel distribution for improved throttle response and mid-to-high RPM efficiency.
• Black finish offers a durable, street-ready appearance with performance compatibility across a range of GM LS builds.
• Comprehensive fuel rail and hardware kit included, simplifying installation and ensuring you have the essential components for EFI conversion in one package.
• Clearance and fitment considerations included: bonnet clearance check due to 122mm overall height ensures proper fitment on many vehicle combinations.