Holley EFI Gen III Hemi Hi-Ram EFI Manifold

2005–2010 Dodge 6.1L / 2009+ Dodge 5.7L / 2011+ Dodge 6.4L Gen III Hemi Engines

300-658BK

Overview:

The Holley EFI Gen III Hemi Hi-Ram EFI Manifold is a high-performance intake solution designed specifically for Dodge Gen III Hemi engines ranging from 5.7L to 6.4L. Engineered to maximize airflow and fuel delivery, this cast aluminum manifold features large intake ports and a modular base that supports a variety of EFI tops, making it an ideal foundation for custom induction setups. Whether you’re building a naturally aspirated, forced induction, or nitrous-assisted engine, the Hi-Ram manifold delivers exceptional power potential at high RPMs, making it perfect for muscle cars, drag racing, marine, off-road, and street rod applications.

Its bold, race-inspired styling not only enhances engine bay aesthetics but also signals serious performance intent. Designed for engines operating up to 7.2+ liters and optimized for peak power between 7,500 and 8,500 RPM, this manifold is a versatile upgrade for enthusiasts seeking to unlock the full potential of their Gen III Hemi powerplants.

Key Features:

Built with precision and performance in mind, the Holley Hi-Ram EFI manifold offers a range of advanced features:

• Cast-in pads for easy installation of nitrous nozzles, supporting nitrous oxide applications
• Billet oil fill cap with a sleek, low-profile design for a clean engine appearance
• Compatibility with Gen III Hemi injectors and Bosch EV-1 style fuel injectors for flexible fuel delivery options
• Port for OE-style manifold absolute pressure (MAP) sensors (1 or 2 bar) to support accurate EFI tuning
• Runner length and tapered cross-section optimized for a wide range of engine configurations and performance goals
• Designed to fit Gen III Hemi engines with large intake ports measuring 1.70” height by 1.88” width
• O-ring seal to cylinder head with large retained O-rings for superior OE-style sealing and easy maintenance
• Modular manifold base available separately for custom induction system builds
• Positive crankcase ventilation (PCV) ports with adapter fittings for proper crankcase venting
• Includes EFI fuel rails machined for -8 AN O-ring fittings with large passages to support high fuel flow and reduce pressure pulsations

Construction & Design:

The Hi-Ram manifold is crafted from durable cast aluminum, available in a natural satin or black finish to suit your build’s aesthetic. Its robust construction ensures long-lasting reliability under demanding conditions. The design incorporates large intake ports and a tapered runner cross-section to optimize airflow velocity and volume, enhancing volumetric efficiency across a broad RPM range. The modular base allows fabricators and builders to customize the induction system by pairing it with various EFI tops, making it a versatile platform for both street and race applications.

Performance & Sound

By increasing intake airflow and improving fuel atomization, the Holley Hi-Ram manifold significantly enhances engine breathing, enabling higher horsepower and torque outputs at elevated RPMs. This manifold is engineered to support maximum power production in the 7,500 to 8,500 RPM range, making it ideal for high-revving naturally aspirated engines as well as boosted or nitrous setups. The aggressive intake design also contributes to a more pronounced induction sound, adding to the overall performance character of your Gen III Hemi.

Installation & Fitment:

This manifold is designed to bolt directly onto 2009 and newer 5.7L, 2005 to 2010 6.1L, and 2011 and newer 6.4L Gen III Hemi engines with large intake ports. Installation requires no major modifications, and the included O-ring seals provide a reliable, leak-free connection to the cylinder heads. The manifold’s modular design allows for easy integration with existing EFI systems and supports a variety of fuel injector types and sensor configurations. Professional installation is recommended to ensure optimal performance and proper tuning.

What's Included:

• Holley Hi-Ram EFI intake manifold (black finish)
• EFI fuel rails with -8 AN O-ring fittings
• Billet oil fill cap
• O-ring seals for cylinder head mounting
• PCV adapter fittings

Ideal For:

This manifold is perfect for performance enthusiasts and professional builders seeking to maximize power on Gen III Hemi engines in muscle cars, drag racers, marine vessels, off-road vehicles, sandrails, pulling trucks, and street rods. It excels in naturally aspirated, forced induction, and nitrous applications, especially where engine bay height is not a limiting factor. If you want a race-bred, aggressive intake manifold that delivers both style and substance, the Holley Hi-Ram EFI manifold is an excellent choice.

Holley EFI delivers standalone engine management and EFI systems built for everything from engine swaps to serious horsepower builds. With platforms like Sniper, Terminator X, HP, and Dominator, Holley EFI is aimed at enthusiasts who want modern tuning control, data, and drivability—whether it’s a street car, track car, or full-on race program.