SKU: 44351327302

Holley LS Hi-Ram EFI Manifold - Black - 300-123BK

Sale price$562.48 Regular price$624.98
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Ships within 48 hours · Estimated delivery Sep 13 - Sep 18

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Description

Holley LS Hi-Ram EFI Manifold - Black - 300-123BKOverview: The Holley GM LS1 LS2 LS6 Modular Hi Ram Intake Manifold is introduced as a cost effective alternative to fabricated sheet metal for high performance applications where induction system height is not limited. Coupling this Hi Ram intake with the high flowing LS1 LS2 LS6 style cylinder heads has outstanding potential for N A and forced induction applications at a budget minded cost. Aggressive, bold, race bred styling will make bad intentions

Overview:

The Holley GM LS1/LS2/LS6 Modular Hi-Ram Intake Manifold is introduced as a cost effective alternative to fabricated sheet-metal for high-performance applications where induction system height is not limited. Coupling this Hi-Ram intake with the high flowing LS1/LS2/LS6 style cylinder heads has outstanding potential for N/A and forced induction applications at a budget-minded cost. Aggressive, bold, race-bred styling will make bad intentions clear for drag race, muscle car, marine, off-road, sandrails, pulling trucks, track, street-rod applications and more!  The base is designed to be modular in configuration to accept a wide range of carbureted and EFI tops and to be attractive to builders and fabricators as the foundation for custom induction systems.  Runner length and the tapered cross-section designed to perform well for a wide range of engine configurations  EFI fuel rails are machined for -8AN O-ring Fittings with passages large enough to accommodate high fuel flows and dampen pressure pulsations in the fuel system and come standard with EFI Hi-Ram kits.  Cast aluminum construction.  Intended for use on N/A or forced induction engines in the 6.0 to 7.0+ liter range, max power at 7000-8000+RPM.

Features:

  • Base Plenum Top Mounting Flange Height – 8.42” to the lifter valley cover flange on engine block.
  • Total Height with 92/105mm EFI Plenum Top – 12.32” to the lifter valley cover flange on engine block.
  • Runner Length – 6.58”, As-Cast Runner Cross-Sectional Area – Tapered 4.25 in² to 2.53 in²
  • Throttle Body Flange Location, with 102mm EFI Plenum Top : Height – 8.42” (from engine block lifter valley cover flange), Longitudinal Location – 3.84” (forward from engine block front flange), Angle – 25 deg. (down from vertical)
  • Plenum Top Gasket Type – 3/32” Round O-ring Cord
  • Mounting Flange Gasket Type – Standard LS3 Molded O-Ring
  • Port Size – 2.49” Height x 1.21” Wide

 

Application:

Year Make Model Submodel Engine Size
Universal

 

Specs:

Brand Holley EFI
Color Black
Construction Cast
Emission Code 3
Engine GM Small Block Gen III/IV (LS Based)
Finish Black
Front Height 12.32 inch
Fuel System Type EFI
Manifold Type Hi-Ram
Product Type Manifold
Rear Height 11.00 inch
RPM Power Band 1500-7000
Warranty Limited 90 Day
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 44351327302

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Cee
Bozeman, US
★★★★★ 5
Best butyl out there.
Style: 30 sqft
If you want the money you're spending on equipment to pay off, you NEED to deaden sound! I've used every major brand and siless is my favorite to work with and the best value for your money, I'm not just adding weight, it's a thermal barrier and reduce outside noise. I turned a 10 year old, base model civic into what feels like a top tier Lexus . Does not offgas, no smell. Super easy to install. Make sure you get a set of rollers! They're required to achieve the advantages of this stuff, it MUST be adhered well and you don't want to tear the interior out twice.
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Reviewed in the United States on August 10, 2025
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Amazon Customer
Port Orchard, US
★★★★★ 5
Yes
Style: 30 sqft
Easy to work with, quiets doors very well, cuts very easily to any shape needed or wanted with scissors, sticks well, and molds in to place well
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Reviewed in the United States on May 11, 2026
M
Verified Purchase
Mathew Pullin
Houston, US
★★★★★ 5
Easy to install and easy to cut! Good quality
Style: 30 sqft
Details in the video! Only used dynamat in the past so I was hesitant to use this. Hesitant no more and the price was good. Good value, easy install, very happy!
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Reviewed in the United States on January 26, 2026
G
Verified Purchase
GS_adventure_Guy
Battle Creek, US
★★★★★ 5
Worth every penny
Style: 6 sqft
Works great! I have a van and it took all the noise out of the rear doors. I am almost in shock at how quiet it is now.
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Reviewed in the United States on May 7, 2026
A
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A Viking
Los Angeles, US
★★★★★ 4
Great for what it does but not a miracle
Style: 30 sqft
Sticks well. Definitely thicker and nicer than the Kilmat version. If I were buying again I would just buy more of this, the value is better even though you get less total coverage per pack. Can be cut to size easily, we used a box cutter which got a little gummed but but not too bad. we were able to get it in and around everywhere we needed to put it and it held up well as we were mashing it into weird spots. It doesnt smell hardly at all while being applied and once its on there is no smell whatsoever The product is great for what it is. 4 stars only because I think it gets oversold for how much this alone can do. We did notice a slight reduction in noise but nowhere near the multiple decibels we see claimed everywhere. If your vehicle is mostly quiet but just has that little bit getting through this will probably do wonders, If you have a vehicle where there's significant engine noise in the cabin you'll need more than just this to bring that down.
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Reviewed in the United States on September 12, 2025

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