EVIL ENERGY LS1 LS2 LS6 Single Plane Intake Manifold & 750 CFM 4-Barrel Carburetor Kit

LS1 LS2 LS6 Single Plane Intake Manifold & 750 CFM Carburetor Kit

Converting an LS engine from EFI to a carbureted setup requires the intake manifold, carburetor, ignition control, fuel delivery, and installation interfaces to work as one system. This EVIL ENERGY LS carburetor intake kit pairs a single plane manifold for compatible LS1, LS2, and LS6-style cathedral-port engines with a 750 CFM carburetor for modified LS combinations focused on higher-RPM operation.

This combination is better suited to performance-oriented LS builds than to engines configured mainly for low-RPM cruising or maximum low-speed torque. The manifold's listed operating range is 5,000-7,500+ RPM, so the complete engine, valvetrain, cylinder heads, camshaft, ignition, fuel system, and drivetrain should be capable of supporting the intended operating range.

Fitment first: Confirm the actual cylinder-head port style before ordering. This intake is designed for compatible cathedral-port configurations and is not intended for LS3, L92, L99, L76, or other rectangular-port heads unless compatible cathedral-port cylinder heads have been installed.

Is This Kit Right for Your LS Build?

Is a 750 CFM Carburetor Right for Your Engine?

A 750 CFM carburetor is not automatically the right choice for every LS1, LS2, or LS6. Required airflow depends on displacement, maximum RPM, volumetric efficiency, camshaft profile, cylinder-head airflow, compression ratio, exhaust, gearing, and intended use.

This combination is better aligned with modified LS engines that can use the higher-RPM characteristics of the single plane intake. A stock or lightly modified 5.7L engine that spends most of its time at lower RPM may be better matched to a different carburetor or intake configuration.

The included performance carburetor uses air valve-controlled secondaries, allowing additional secondary airflow to increase according to engine demand rather than tying secondary airflow directly to throttle movement. This provides a more progressive secondary transition than a directly linked mechanical-secondary arrangement.

Why Choose a Single Plane Intake for a Carbureted LS?

A single plane intake uses a common plenum feeding the intake runners and is generally selected when higher-RPM airflow is more important than maximizing low-speed response. This makes the manifold better suited to appropriately configured performance street, street/strip, track, hot rod, and carbureted LS swap combinations that operate regularly at higher engine speeds.

The listed manifold RPM range describes the intended operating characteristics of the intake manifold; it is not a safe engine-speed guarantee. Maximum engine RPM must be determined from the complete rotating assembly, valvetrain, cylinder heads, camshaft, oiling system, ignition control, and calibration.

LS1 LS2 LS6 Cathedral-Port Fitment

This LS carburetor intake is designed around compatible GM LS Gen III and Gen IV engines equipped with LS1, LS2, or LS6-style cathedral-port cylinder heads. Compatible combinations may include 5.7L LS1 and LS6 engines, 6.0L LS2 engines, and other verified cathedral-port LS builds.

Reference vehicle applications may include Corvette C5, Camaro, Firebird / Trans Am, Pontiac GTO, Cadillac CTS-V, Chevrolet SSR, Holden Monaro / Commodore / HSV, and LS-swapped vehicles using a compatible engine configuration.

Vehicle year, make, and model alone do not confirm fitment. Engine swaps, cylinder-head changes, and previous modifications can change intake compatibility. Confirm the cylinder heads actually installed on the engine before ordering.

Not compatible with LS3, L92, L99, or L76 rectangular-port cylinder heads unless the engine has been converted to compatible cathedral-port heads.

What Else Is Needed for an LS Carburetor Conversion?

An LS carburetor conversion involves more than replacing the EFI intake. The carburetor meters airflow and fuel, but compatible ignition control, fuel pressure, mechanical linkage, choke operation, vacuum connections, and installation clearance still need to be established separately.

Package Contents

Additional Parts to Check Before Ordering

The exact installation parts depend on the engine and vehicle configuration. Check whether the build requires:

• Compatible LS ignition controller
• Intake manifold and carburetor gaskets
• Carburetor-compatible fuel pump and/or fuel pressure regulator
• Fuel filter, fuel lines, fittings, and adapters
• Throttle cable bracket and return springs
• Transmission kickdown or TV cable components where applicable
• Manual choke cable
• Vacuum and PCV fittings
• Air cleaner assembly
• Carburetor spacer or adapter if required by the final configuration

Before Installation

• Confirm the cylinder heads: Verify LS1, LS2, LS6, or another compatible cathedral-port configuration.
• Check intake fitment: Verify intake-port alignment, bolt pattern, and intake gasket compatibility.
• Check the carburetor interface: Confirm the mounting pattern, gasket, studs, and whether a spacer or adapter is required.
• Plan ignition control: Establish a compatible ignition-control strategy before converting from EFI to carburetor operation.
• Verify the fuel system: Confirm the pump, regulator, filter, lines, and fittings are appropriate for carburetor fuel pressure.
• Check throttle operation: Verify the throttle cable, bracket, return springs, and transmission linkage through the full range of travel.
• Check manual choke operation: Confirm cable routing and complete choke travel.
• Check vacuum connections: Identify required PCV, brake-booster, and accessory vacuum ports before startup.
• Check clearance: Include the manifold, carburetor, spacer or adapter, and air cleaner when measuring hood and surrounding engine-bay clearance.

Initial Setup & Tuning

Final carburetor calibration depends on the complete engine combination. Before changing jets or metering components, verify the installation and supporting systems first.

1. Inspect the intake manifold, carburetor base, vacuum connections, and fuel connections for leaks.
2. Confirm that fuel pressure and fuel delivery are appropriate for the carburetor.
3. Verify ignition control and timing operation.
4. Check throttle and manual choke movement through their full range.
5. Set and evaluate idle speed and idle mixture after the engine reaches operating temperature.
6. Evaluate transition and secondary operation before changing the metering calibration.
7. Change one calibration variable at a time and record the result.

Do not automatically treat rich, lean, bogging, unstable-idle, or hard-start conditions as a jetting problem. Check for vacuum leaks, incorrect fuel pressure, fuel-delivery problems, float or needle-seat issues, ignition faults, and timing problems before changing carburetor calibration.

Brand Summary

Return Reasons

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2. Wrong Item Ordered: Buyer covers return shipping; email within 30 days.
3. Change of Mind: Buyer covers return shipping; email within 30 days.
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5. Incorrect Item Shipped: Contact within 7 days.

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Effective from August 25, 2024. Price drops within 7 days of purchase can be claimed.

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