LS Cathedral Port Carburettor Hi Rise Race Single Plane EFI Manifold

LS Cathedral Port Hi Rise EFI Single Plane Manifold for GM LS1/LS2 Cathedral Port Heads

Elevate your GM LS engine performance with this Cathedral Port Hi Rise EFI intake manifold. Featuring a natural cast finish and a 4150 square-bore carburettor pad, it’s designed specifically for GM LS1/LS2 cathedral port heads and EFI applications, delivering focused air and fuel delivery across a wide RPM range.

Key Features

• Single Plane, High Rise configuration for steady air/fuel distribution from 2500 to 7000 RPM
• Carburettor pad: 4150 square-bore flange
• Fits GM LS1/LS2 Cathedral Port engines; EFI applications only (AF6040-5005 for NON-EFI)
• Overall height from carb pad to bottom: 172 mm (bonnet clearance should be checked)
• Port size: 1.08" x 2.45"
• Gasket requirement: Fel Pro 1312-2 or 1312-3
• Carburettor studs: 5/16-18" x 4
• Fuel rail mounting: 4 M6 x 1.00 mm mounting holes for fuel rails
• Includes intake manifold hardware: 10 x M6 x 1.00 mm hex screws (50 mm UHL) and 10 x flat washers
• Note: Not compatible with factory OEM fuel rails; Aeroflow Fuel Rail Kit AF6999-5000 included
• Injector requirement: uses 14 mm short injectors (33.60 mm) — sold separately

What’s Included

• Intake manifold (Natural Cast Finish) with 10 x M6 x 1.00 mm hex screws (50 mm UHL) and 10 x M6 flat washers
• Fuel Rail Kit includes:
  • 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

Designed to keep air and fuel flowing smoothly into GM LS Gen III and IV engines equipped with OE or aftermarket LS1/LS2 cathedral port heads, this Hi Rise Race intake is tailored for turbocharged and high-performance EFI setups. It enables a retrofit path for a 4150-style throttle body when paired with the included Aeroflow Rail Kit, delivering a cohesive, race-ready EFI solution without guessing on compatibility.