HOLLEY EFI 300-121BK Ls Manifold Dual Plane Gm 090127715857 LS1/LS2/LS6

( Brand: Holley Efi ), ( Part Type: Manifold ), ( Material: Aluminum ), ( Color: Black ), ( UPC: 090127715857 ), ( Manufacturer Part Number: 300-121BK )

Review HOLLEY EFI Ls Manifold Dual Plane Black Gm Ls1/ls2/ls6 fits LS1 LS2 LS6 2X4

The Holley EFI 300-121BK LS Manifold is a high-performance intake manifold specifically designed for GM LS1, LS2, and LS6 engines. This manifold is part of Holley's EFI (Electronic Fuel Injection) product line, which is known for its precision, reliability, and power gains.

This dual-plane intake manifold is constructed from high-quality aluminum, ensuring a strong and durable design. Its dual-plane configuration provides excellent throttle response and an even fuel distribution between cylinders, leading to improved engine performance. The manifold's runners are designed with a large bore size and optimized port geometry, allowing for maximum airflow and efficient combustion.

The Holley EFI 300-121BK LS Manifold is equipped with Holley's proprietary port injector mounting system. This system allows for the easy installation of port fuel injectors, providing precise fuel delivery and a more efficient combustion process. The manifold also includes provisions for factory-style vacuum ports and a factory-style power steering ID plate, making it a direct swap for the stock manifold.

The intake runners are designed with a large plenum volume, which reduces turbulence and promotes smooth airflow into the engine. The manifold also features a high-performance, fully-sealed gasket and bolt kit, ensuring a proper seal and eliminating the need for messy gasket materials.

This manifold is a great option for enthusiasts looking to upgrade their LS engine's intake system for improved performance and efficiency. Its high-quality construction, optimized port geometry, and easy install make it a popular choice among performance builders and racers. With the Holley EFI 300-121BK LS Manifold, you can expect increased horsepower, better throttle response, and improved fuel economy.

The Holley EFI 300-121BK LS Manifold is a dual-plane intake designed for use with General Motors LS1, LS2, and LS6 engines. This intake system is known for its high-performance capabilities, but like any automotive part, it comes with its pros and cons.

1. High-Performance: The Holley EFI 300-121BK LS Manifold is designed to deliver improved airflow and power gains compared to stock intake systems. This is due to its dual-plane design, which provides better flow distribution to each cylinder.

2. Fuel Injection Compatibility: This intake system is specifically designed for use with electronic fuel injection systems, making it a popular choice for performance enthusiasts looking to upgrade their factory fuel injection setup.

3. Improved Throttle Response: By providing better airflow to the engine, the Holley EFI 300-121BK LS Manifold can improve throttle response, resulting in a more responsive driving experience.

4. Customizable: Holley offers various options for this intake system, including different runners lengths, port sizes, and even different materials. This allows customers to tailor the intake to their specific engine build and performance goals.

1. Expensive: Compared to stock intake systems, the Holley EFI 300-121BK LS Manifold is a significant investment. This may not be a concern for serious performance enthusiasts, but it could be a deterrent for those on a tight budget.

2. Installation Complexity: Installing this intake system can be a complex process, especially for those without experience in engine performance modifications. Professional installation is recommended for optimal results.

3. Potential for Leaks: Due to the complex nature of the intake system, there is a potential for leaks. Proper installation and maintenance are essential to ensure that the intake system functions efficiently and without leaks.

The Holley EFI 300-121BK LS Manifold is a high-performance intake system designed for serious performance enthusiasts looking to upgrade their LS engine's airflow and power. While it comes with some cons, such as expense and installation complexity, the benefits, including improved throttle response and compatibility with fuel injection systems, make it a worthwhile investment for those looking to take their LS engine to the next level.

If you're a performance enthusiast with a LS1, LS2, or LS6 engine and a significant budget, the Holley EFI 300-121BK LS Manifold is a worthwhile investment. However, it's essential to ensure proper installation and maintenance to ensure optimal performance and prevent potential leaks. If the cost or installation complexity is a concern, consider alternative intake systems that may offer similar performance benefits but at a lower cost or installation complexity.

Details:

300-121BK Holley LS EFI Manifold - 2X4 Dual Plane Black GM LS1/LS2/LS6: Intake Manifold, Gen 3 LS1/LS2/LS6 engines, w/Black Ceramic Coating. OE LS fuel injectors may not fit properly in the Hi-Ram EFI intake manifold rail assembly. Buyer pays return shipping. X000D NOTE: The EFI versions of the LS HI-Ram intake manifold and fuel rail are designed to accept Bosch EV-1 or Magneto Marvell Picot injectors.

All GM LS Gen 3 engines equipped with LS1/LS2 cathedral port cylinder heads.

part #: 300121bk price

• $819.95

specifications inputmanifolds:

• for models: Ls1, Ls2, Ls6, 2x4
• brand: Holley Efi
• part type: Manifold
• material: Aluminum
• color: Black
• upc: 090127715857
• manufacturer part number: 300-121BK

returns inputmanifolds:

• policy: Returns Accepted
• paid by: Seller
• time: 30 Days

offer inputmanifolds:

• quantity: 3
• sold: 0
• started: August 12, 2025
• options: Ship-to-home
• availability: In Stock

payments inputmanifolds:

• wallet: Apple-pay
• other
• credit card: Visa

shipping inputmanifolds:

• carrier: UPS
• cost: $0.00
• transit: 3-5 Days
• service: UPS Ground
• type: Fixed
• class: Standard

seller inputmanifolds:

• rating: 98.9%
• # reviews: 15372
• city: Bowling Green, Kentucky

general inputmanifolds:

• condition: New
• Car Truck Parts Accessories > Air Fuel Delivery > Intake Manifolds

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