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Holley EFI

Plenum top for Ultra Lo-Ram 300-621

Satin Finish

Part # 300-604
In Stock
Your Price
$152.95
Suggested Retail
$170.00
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The Holley LS1/2/6 Ultra Lo-Ram intake manifold kits are designed for GM LS Gen III and IV engines equipped with GM LS1/2/6 (cathedral port) cylinder heads. These intake manifold and rail kits will work with OE or aftermarket cylinder heads. The 300-604 is the plenum top in the 300-621 complete kit. Offering this separately allows you to select your components individually as you build your system. The Lo-Ram intake manifolds are designed for forced induction (supercharged or turbocharged) engine applications and the 105 mm throttle body part number 112-581 or similar models. The base intake manifold is designed with a lower overall height to fit under a stock or mildly modified hood. The 300-621 Lo-Ram plenum entry was configured to provide a very low profile modular intake manifold suitable for turbocharged or centrifugally supercharged engines. The fuel rail kits come with two sets of brackets. A set for long (usually standard length) fuel injectors and a set for short (such as Pico, or LS7) fuel injectors.

Features:

  • Individual plenum top for 300-621 allows you to select your components individually as you build your intake system
  • Designed for GM LS Gen III and IV engines equipped with GM LS1/2/6 (cathedral port) cylinder heads
  • Designed for forced induction (supercharged or turbocharged) engine applications with peak power at 7000-8000 rpm depending on the application
  • Modular design allowing the use of the included front plenum entry
  • Intake design facilitates custom inlet duct and throttle body placement
  • Low height to fit under a stock or mildly modified hood.
  • Front entry plenum flange allows design & fabrication of special throttle body adapters or inlet ducts for custom installations
  • Clears 1998-2002 (4th Gen) Camaro/Firebird and 1997-2004 (C5) Corvette cowls and hoods without modification
  • High volume fuel rails and mounting hardware included with ¾”-16 o-ring ports (8 AN)

About Holley EFI

Holley is the new standard in EFI! Whether you're engine swapping your classic street car or need to manage 4000 horsepower in your twin-turbocharged drag radial race car, Holley EFI has the solutions you need to get your project up and running better than ever!

BrandHolley EFI
ColorSilver
Emission Code3
EngineGM LS1/LS2/LS6
FinishCast
Fuel System TypeEFI
Manifold TypeUltra Lo-Ram
Product TypeIntake Manifold Top
WarrantyLimited 90 Day
UPC090127077504
Part Number300-604
3

This part is legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles and Racing Use Only Vehicles.

The following vehicles are considered Uncontrolled (Non-Emissions Controlled) Vehicles:

  • 1965 and older U.S. manufactured California Certified vehicles
  • 1967 and older U.S. manufactured Federally Certified vehicles
  • 1967 and older Foreign manufactured vehicle

The following vehicles are considered Racing Use Only Vehicles:

  • Racing Use Only Vehicles are vehicles that are used exclusively for competition and that are not registered and that may never be used on the street

WARNING: It is against the law to install this part on an Emissions Controlled Vehicle

The following vehicles are considered Emissions Controlled Vehicles:

  • 1966 and newer U.S. manufactured California Certified vehicles
  • 1968 and newer U.S. manufactured Federally Certified vehicles
  • 1968 and newer Foreign manufactured vehicle
Limited 90 Day: See Details

*Free Shipping & Handling only offered to the contiguous US on orders over $100, excludes clearance parts and oversized packages.

Some parts are not legal for use in California or other states with similar regulations.