Holley EFI - Holley Modular Ultra Lo-Ram EFI Manifold LS1/2/6 300-621BK
Type: Intake Manifold | Fits: Ram
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.
The 300-621 Ultra Lo-Ram front-feed 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:
- 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.
- 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 ¾”-16 o-ring ports (8 AN)
Specs:
- Basic Operating RPM Range: 3500-8000 RPM
- Brand: Holley EFI
- Category: Intake Manifolds
- Color: Black
- Construction: Cast
- EGR Port: No
- Emission Code: 3
- Engine: GM LS1/LS2/LS6
- Finish: Black
- Flange Style: EFI
- Front Height: 6.86" height with throttle body adapter
- Front Maximum Height: 6.86 IN
- Fuel Injectors Included: No
- Fuel Rail(s) Included: Yes
- Fuel System Type: EFI
- Gasket Or Seal Included: No
- Grade Type: Performance
- Injector Quantity: Single
- Inlet Location: Front
- Intake Port Gasket(s) Included: No
- Manifold Type: Ultra Lo-Ram
- Material: Aluminum
- Nitrous Bung(s) Included: No
- Plenum Finish: Black
- Product Type: Intake Manifold
- Recommended Use: Forced Induction
- Removable Runners: No
- RPM Power Band: 3500-8000 RPM
- Single Or Dual Plane Type: Single Plane
- Throttle Body Bore Diameter: 105 MM
- Throttle Body Included: No
- Warranty: Limited 90 Day
Tech Resources:
Lo-Ram Base Intake Manifold Plenum Top Mounting Flange Height - 5.17"
Front Feed Plenum Configuration w/105mm Throttle Body Adapter - 6.86"
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Important Notices
- Professional Installation Recommended
These parts should be installed by qualified professional mechanics. Improper installation can cause performance issues or vehicle damage. Unless a product page explicitly states otherwise, installation instructions are not included. Components are designed for users with solid mechanical knowledge, and minor adjustments or modifications may be required for proper fitment. Returns or refunds cannot be accepted due to difficulty completing an installation or the absence of instructions. - Warranty Impact
Use of these parts may void your vehicle’s factory warranty. Confirm with your vehicle manufacturer before purchase and installation. - Limitation of Liability
JS Speed is not responsible for damage, failures, or issues arising from the use or installation of these products. - Product Images
Images are for illustration only and may differ from the actual product due to manufacturer updates or improvements. - No Performance Guarantees
While these products are designed to enhance performance, JS Speed does not guarantee specific performance results.
