Oldsmobile Big Block V8 Dual Plane Air Gap Aluminum Intake Manifold - Polished

• Air-gap design helps reduce heat transfer

• Dual-plane runners improve torque and throttle response

• Fits Oldsmobile 400, 425 & 455 big block engines

• Polished 6061-T6 aluminum construction

Upgrade your Oldsmobile big block with the Top Street Performance Dual Plane Air Gap Intake Manifold. Designed for carbureted Oldsmobile 400, 425, and 455 V8 engine applications, this polished aluminum intake manifold combines the low-end torque and drivability of a dual-plane design with the airflow advantages of an air-gap intake manifold. Whether you're building a 442, Cutlass, Delta 88, Toronado, street machine, bracket car, or performance street build, this intake manifold is engineered to deliver improved airflow, stronger throttle response, and increased power throughout the operating range.

The air-gap plenum design creates an open space beneath the intake runners to reduce heat transfer from the engine into the incoming air/fuel mixture. By helping maintain a cooler intake charge, the manifold supports improved combustion efficiency and stronger power production while maintaining the street-friendly characteristics enthusiasts expect from a dual-plane intake.

Unlike many single-plane manifolds that sacrifice drivability for peak horsepower, the dual-plane air-gap design provides power and torque characteristics comparable to more aggressive race-style intakes while maintaining responsive throttle control and excellent street manners. This makes it an excellent choice for performance street cars, weekend cruisers, street/strip combinations, and bracket racing applications.

Designed to perform best between 1,500 and 6,500 RPM, the manifold delivers a broad usable powerband that complements a wide range of Oldsmobile big block combinations. The 4150 square-bore carburetor flange supports popular performance carburetor setups commonly used on Oldsmobile V8 engines.

Constructed from heat-dissipating 6061-T6 aluminum, the manifold helps reduce weight compared to factory cast iron intake manifolds while improving heat management and engine bay appearance. The polished finish delivers a show-quality look, while the relatively low-profile design helps improve hood clearance in many applications.

Air-Gap Technology
The open air-gap plenum helps isolate the intake runners from engine heat, reducing heat transfer into the incoming air/fuel mixture. This design helps maintain a cooler intake charge for improved power and torque production.

Street & Strip Performance
Designed to operate from 1,500 to 6,500 RPM, the dual-plane runner layout delivers strong low-end torque, responsive throttle control, and broad mid-range power while maintaining excellent street drivability.

Performance Features
Features include a 4150 square-bore carburetor flange, dual-plane air-gap runner design, lightweight aluminum construction, and a low-profile profile that can help improve hood clearance in many applications.

Lightweight Aluminum Construction
Constructed from heat-dissipating 6061-T6 aluminum, the manifold helps reduce weight compared to factory cast iron intakes while providing durability and a polished finish for performance-oriented engine compartments.

Will this intake manifold fit an Oldsmobile 455 engine?
Yes. This intake manifold is designed for Oldsmobile big block applications including 455 cubic inch engines.

Will this intake manifold fit an Oldsmobile 400 engine?
Yes. Published fitment includes Oldsmobile 400 engine applications.

What is the benefit of an air-gap intake manifold?
The air-gap design creates an open space beneath the plenum to reduce heat transfer from the engine, helping maintain a cooler air/fuel charge for improved power and torque.

What RPM range is this intake manifold designed for?
The manifold is designed to perform from approximately 1,500 to 6,500 RPM.

What carburetors does this intake manifold support?
The manifold uses a 4150 square-bore carburetor flange and is designed for single 4-barrel carburetor applications.

Is this a good upgrade from a stock intake manifold?
Yes. The aluminum air-gap design helps improve airflow, throttle response, and overall performance compared to many factory cast iron intake manifolds.