LS1 Cathedral Port Carburettor Hi Rise Single Plane Intake Manifold Black

Overview

Convert your GM LS engine from EFI to a non-EFI carburettor with the LS1 Cathedral Port Hi Rise Single Plane Intake Manifold in a bold black finish. This hi-rise, Super Victor‑style cast intake delivers steady air and fuel distribution at high rpm, ideal for retro-fit carburettor setups on LS Gen III and IV cathedral port heads.

Compatibility & Use

• Designed for GM LS Gen III and IV engines equipped with OE or aftermarket LS1/LS2 cathedral port heads.
• Intended for carburetted, throttle body EFI, or port EFI applications.
• Hi‑Rise single‑plane configuration optimized for high rpm and large displacement builds.

Key Features

• 4-barrel 4150 square‑bore carburettor pad (4150 flange) for aftermarket square-bore carburettors.
• Overall height from carb pad to bottom: 171 mm — check bonnet clearance before installation.
• Port size: 1.08" x 2.50".
• Intake gasket interface: flat style gasket; must use Fel Pro 1312-2 or 1312-3.
• Carburettor mounting hardware: 5/16-18" carburettor studs (x4).
• Includes installation hardware: 10 x M6 x 1.00 mm hex screws (50 mm UHL) and 10 x M6 flat washers.
• Finish: durable black powder-coated/manufactured finish for a stealthy, race‑ready look.

What You Get

• Intake manifold with hi‑rise, single‑plane design for even air/fuel distribution at high rpm.
• Hardware kit: M6 screws and washers for mounting (quantity specified above).
• Carburettor pad prepared for aftermarket 4150 square‑bore carbs with either manual or electric choke options.

Performance & Installation Notes

• RPM operating range: 3500 to 8000, suited for high‑rpm racing or performance street builds.
• Hi‑Rise design supports larger cubic inch applications where scavenging and plenums benefit from increased velocity at higher engine speeds.
• Bonnet clearance is a critical consideration due to the 171 mm manifold height; verify space before purchase.