Holley EFI Gen III Hemi Hi-Ram EFI Manifold

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

300-658

Overview:

The Holley EFI Gen III Hemi Hi-Ram EFI Manifold is a high-performance intake solution designed specifically for Gen III Hemi engines ranging from 5.7L to 6.4L displacement. Engineered to maximize airflow and fuel delivery, this cast aluminum manifold is ideal for enthusiasts seeking to extract more power from naturally aspirated, forced induction, or nitrous-equipped setups. Its large intake ports and precision-machined EFI fuel rails support high fuel flow rates while reducing pressure pulsations, ensuring consistent and efficient combustion at high RPMs.

Whether you are building a muscle car, drag racer, off-road machine, or street rod, the Holley Hi-Ram manifold offers aggressive styling and race-bred performance. It is designed for applications where induction system height is not a limiting factor, making it a versatile choice for a wide range of high-output Gen III Hemi builds.

Key Features:

This intake manifold combines advanced engineering with practical features to enhance power and reliability:

• Cast aluminum construction with a natural satin or black finish for durability and style
• Large intake ports measuring 1.70” height by 1.88” width, compatible with 2009+ 5.7L, 2005–2010 6.1L, and 2011+ 6.4L Gen III Hemi engines
• EFI fuel rails machined for -8AN O-ring fittings, featuring large passages to support high fuel flow and dampen pressure pulsations
• Cast-in pads for easy installation of nitrous nozzles, expanding tuning possibilities
• Positive Crankcase Ventilation (PCV) ports with adapter fittings for proper engine ventilation
• Port for OE-style Manifold Absolute Pressure (MAP) sensor (1 or 2 Bar) to maintain accurate engine management
• Modular base design allowing compatibility with a wide range of EFI tops and custom induction setups
• Runner length and tapered cross-section optimized for broad engine configurations and RPM ranges
• Billet oil fill cap with a low-profile, attractive design
• Large retained O-ring seals for superior OE-style sealing and easy maintenance

Construction & Design:

The Holley Hi-Ram manifold is crafted from high-quality cast aluminum, providing a lightweight yet robust foundation for high-performance applications. Its satin or black finish offers corrosion resistance and a sleek appearance that complements any engine bay. The design features large, tapered runners that promote efficient airflow and fuel atomization, supporting maximum power output at elevated RPMs between 7,500 and 8,500.

The modular base allows builders and fabricators to customize their induction systems by pairing the manifold with various EFI tops. Precision-machined fuel rails and O-ring fittings ensure leak-free fuel delivery, while the cast-in nitrous nozzle pads and PCV ports add versatility for different power adders and engine management setups.

Performance & Sound

Optimized for high-RPM power, the Holley Hi-Ram manifold enhances throttle response and volumetric efficiency on Gen III Hemi engines. Its large intake ports and tapered runners improve airflow dynamics, supporting aggressive cam profiles and forced induction systems alike. The manifold’s design contributes to a more aggressive induction sound, underscoring the performance intent of your build.

Installation & Fitment:

This manifold fits Gen III Hemi engines with large intake ports, including 2009 and newer 5.7L, 2005 through 2010 6.1L, and 2011 and newer 6.4L variants. It is compatible with Gen III Hemi fuel injectors and Bosch EV-1 style injectors. Installation requires standard intake manifold procedures and may necessitate custom tuning to optimize fuel and ignition parameters for your specific setup. The modular design also allows for easy integration into custom induction systems.

What's Included:

• Cast aluminum Hi-Ram intake manifold base
• EFI fuel rails with -8AN O-ring fittings
• Billet oil fill cap
• Adapter fittings for PCV ports
• Provision for OE-style MAP sensor

Ideal For:

The Holley EFI Gen III Hemi Hi-Ram EFI Manifold is perfect for performance enthusiasts and professional builders seeking to maximize power on naturally aspirated, forced induction, or nitrous-equipped Gen III Hemi engines. It excels in drag racing, muscle car restorations, marine applications, off-road vehicles, sandrails, pulling trucks, and street rods where induction system height is not restricted. Its modular design also appeals to fabricators and custom builders looking to create specialized induction setups.

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.