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Air and Fuel› Intake Manifolds and Components

Holley

KIT, INT. MANIFOLD, LS1 LO-RAM, SATIN

$1,181.95 $611.05 Save $570.90

SKU: H00E 300-621

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In Stock
Ships by Nov 18
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INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Holley 300-621 is an Ultra Lo-Ram EFI intake manifold kit designed for GM LS Gen III and IV V8 engines. It features a 105 mm throttle body flange, fuel rails, and cathedral port design, constructed from aluminum with a natural finish. This intake manifold is compatible with various LS engine families including LS1, LS2, LS3, LS6, LS7, LS9, LSA, and LSX.
Show original supplier description

Part #: 300-621

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 manifolds will work with OE or aftermarket cylinder heads. The Ultra 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.

Features:

  • 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.
  • With forced-induction and the short runner length the engine rpm at which peak power occurs is more likely to be coupled to the supercharger or turbocharger being used
  • Modular design allowing the use of front-feed plenum entry
  • Intake design facilitates custom inlet duct and throttle body placement
  • Low height to fit under a stock or mildly modified hood in the front configuration
  • Front entry plenum flange allows design & fabrication of special throttle body adapters or inlet ducts for custom installations
  • Clears 4th Gen Camaro and C5 Corvette cowls and hoods without modification
  • High volume fuel rails and mounting hardware included with ┬╛"-16 o-ring ports (8 AN)

Ultra Lo-Ram Manifold Kit - LS1/2/6

Vehicle Symptoms
  • Engine power falls flat above 6500 rpm on boosted LS builds
  • Stock intake feels restrictive at high rpm under forced induction
  • Heat soak hurts performance during long pulls on the street or track
  • Hood clearance issues with taller intake manifold and turbo piping
Relevant Conversations
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  • Best intake manifold for boosted LS cathedral port heads
  • Holley Ultra Lo-Ram vs Fast LSX intake for turbo setup
  • Holley 300-621 install guide fuel rails and injectors
  • Low profile LS intake manifold that clears stock hood
  • Lo-Ram intake manifold tuning high rpm 7000 8000
  • What injectors fit Holley Lo-Ram fuel rails
  • LS1 blower intake manifold comparison cathedral port
  • Holley Ultra Lo-Ram with 92mm throttle body setup
  • LS intake manifold MAP sensor and vacuum line routing

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

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Specifications

BrandHolley
Part NumberH00E 300-621
Weight25.05 lb

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