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Holley EFI Plenum Top for Ultra Lo-Ram 300-621 300-604

Holley EFI Plenum Top for Ultra Lo-Ram 300-621 300-604
Holley EFI Plenum Top for Ultra Lo-Ram 300-621 300-604Holley EFI Plenum Top for Ultra Lo-Ram 300-621 300-604Holley EFI Plenum Top for Ultra Lo-Ram 300-621 300-604Holley EFI Plenum Top for Ultra Lo-Ram 300-621 300-604Holley EFI Plenum Top for Ultra Lo-Ram 300-621 300-604
$302.99 ea
NEWARRIVING SOONEstimated Ship Date 03/18/2024 (If Ordered Today)19 Available from HOLLEY PERFORMANCE PRODUCTS as of 02/25/2024
Model: 4008356
STANDARD
DELIVERY
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 Performance Products

Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors powered every Monster Energy NASCAR Cup team and nearly every NHRA Pro-Stock champion for four decades. Now, Holley EFI products power these cars and are dominating the performance world. Holley products for GM's popular LS engine are dominating the LS scene as well. Holley's products also include performance fuel pumps, intake manifolds and engine dress-up products for street performance, race and marine applications. As a single solution or partnered with products from other Holley companies we can give you the edge you need over the competition!

Downloads:

Download Name File Size
199r11813.pdf1.09MB

Videos:

Specifications:

Color Silver
Construction Cast
Emission Code 3
Engine GM LS1/LS2/LS6
Finish Silver
Fuel System Type EFI
Manifold Type Ultra Lo-Ram
Part Type Engine Air Intake Housing
Product Type Intake Manifold Top
Recommended Use Forced Induction
Warranty Limited 90 Day

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Holley EFI Plenum Top for Ultra Lo-Ram 300-621 300-604:
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