Holley 300-255 LS1/LS2/LS6 Race Intake Manifold, Square Bore, Single Plane, Aluminum, Natural, Kit

The new Holley Single-Plane Race intake manifold were designed with performance in mind. They feature a race bred, two piece split feature that was previously only found on the most expensive race intakes. The manifold will fit GM LS Gen III engines with cathedral port heads and are intended for 4150 style square bore flanged carburetors or throttle body EFI.

The LS Race single-plane intake manifold was designed for hi-performance/racing engine applications, 5.3 to 6.2+ liter displacement, and maximum engine speeds of 6000-7000 rpm, depending on the engine combination. This single-plane design provides optimal performance across the RPM spectrum while providing maximum performance up to 7000 rpm.

The Holley LS Race manifold incorporates a split feature, which allows disassembly of the intake for direct access to internal plenum and port surfaces, making custom porting and matching a snap. With shoulder bolt locators and O-ring seal, reassembly is simple and precise.

Features:

• A-B Height - 7.32" (0° carb flange angle)
• Port Size- 3.28" Height x 1.10" Wide
• Throttle Body Flange - Standard 4150 for up to 1-3/4" diameter throttle bores
• As-Cast Runner Cross-Sectional Area - 3.5 in² at the runner entry tapered to 2.9 in² at the flange exit
• Maximum performance race design with hood clearance consideration
• Lighter than other split race intakes
• Split feature making porting efforts easy!
• 33 to 50% the price of other split race intakes
• Captured O-ring seals at head ports and split
• Vacuum Port options include (2) 1/8, (1) 1/4, and (1) 3/8, NPT ports at the carb flange
• Billet Fuel Rails and rail mounting hardware included.

Instructions

Instructions - 199R11472.pdf

Emissions Warning
Products sold on this website may not be legal for use on public roads or highways due to Environmental Protection Agency (EPA) restrictions or California Air Resources Board (CARB) emissions regulations. Federal and State regulations may restrict Product installation to pre-emissions regulation (Model Year 1974 or earlier) or to competition/racing vehicles used exclusively in
1) events organized by recognized bodies, authorizing permits for participating drivers.
2) racing event qualification, and3) practice associated with events.
Installation of such products, including driving racing vehicles to and from the track, may be considered illegal “tampering ” or as “defeat device”, and may result in federal and state penalties. It is the purchaser’s responsibility to ensure compliance with all applicable emissions laws, including California’s stricter standards.

Proposition 65 Warning:
This product may contain chemicals known to the state of California to cause cancer, birth defects, or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.