Building a forced induction or nitrous LS1, LS2, or LS6 and need an intake that can keep up? Speed Engineering's single plane mid-rise intake manifold is cast and machined from aluminum with a 4150/4160 square bore carburetor flange and a broad 2500-7000 RPM power band — ideal for centrifugal blowers, turbochargers, or nitrous applications. Compatible with LS1, LS2, LS6, and other Gen 3 cathedral port cylinder heads. Hardware and o-ring gaskets are included, along with a 3/8" vacuum port for accessory and boost reference connections.
⚠️ Important Compatibility Note: Factory fuel rails will NOT work with this manifold. The Speed Engineering billet fuel rail kit (26-1085) is required for installation.
Features:
- Single Plane Mid-Rise Design — Optimized for forced induction and high-RPM power
- Cast and Machined Aluminum Construction — Durable and precision-fit
- 4150/4160 Square Bore Carburetor Flange — Compatible with standard square bore carburetors and throttle bodies
- 2500-7000 RPM Power Band — Broad operating range for street and strip applications
- Ideal for Centrifugal Blowers, Turbochargers, or Nitrous — Engineered for forced induction and nitrous power adders
- 3/8" Vacuum Port — For boost reference, vacuum accessories, or brake booster connections
- Hardware and O-Ring Gaskets Included
- Compatible with LS1, LS2, LS6, and Gen 3 Cathedral Port Cylinder Heads
Compatible Engines:
- LS1 5.7L — Gen 3 Cathedral Port
- LS2 6.0L — Gen 3 Cathedral Port
- LS6 5.7L — Gen 3 Cathedral Port
- Other Gen 3 Cathedral Port LS Engines
FAQ
Will my factory fuel rails work with this manifold?
No. Factory fuel rails will not work with this manifold. The Speed Engineering billet fuel rail kit (26-1085) is required for proper installation.
What cylinder heads is this manifold compatible with?
This manifold is compatible with LS1, LS2, LS6, and other Gen 3 cathedral port cylinder heads.
What is the difference between this manifold and the rectangular port version (26-1084)?
This manifold is designed for Gen 3 cathedral port cylinder heads (LS1, LS2, LS6). The rectangular port version is designed for Gen 4 rectangular port cylinder heads (LS3, L92). They also use different billet fuel rail kits — this manifold requires kit 26-1085, while the rectangular port version requires kit 26-1086. Make sure to select the manifold matching your cylinder head port design.
What carburetor or throttle body fits this manifold?
This manifold uses a 4150/4160 square bore flange, compatible with standard square bore carburetors and throttle body adapters.
Is this manifold good for a forced induction build?
Yes. This single plane mid-rise design is specifically suited for centrifugal blowers, turbochargers, and nitrous applications, with a broad 2500-7000 RPM power band.
Is hardware included?
Yes. Hardware and o-ring gaskets are included with the manifold.
What is the vacuum port size?
This manifold has a 3/8" vacuum port for boost reference, vacuum accessories, or brake booster connections.
Is this manifold street legal?
No. This is a race-only product intended for closed-course competition use only. Installation on a street-driven vehicle may violate the Clean Air Act (42 U.S.C. 7522(a)(3)).
⚠️ Race Use Only: This product is manufactured and sold for installation on vehicles used solely for competition. Once installed, the vehicle may not be used, registered, or licensed for use on a public road or highway. Installation on a street-driven vehicle may violate the Clean Air Act 203(a)(3), 42 U.S.C. 7522(a)(3).