Big Block Chevrolet Engine Intake and Exhaust Manifolds Info and Casting Numbers

Big Block Chevrolet Engine Intake Manifolds

During the many years of production Chevrolet used many different configurations of Cast Iron and Aluminum intake manifold for the Big Block engines. Most standard output Big Blocks came with cast iron spread bore with oval port manifolds. While high-performance engines came with aluminum rectangular port manifolds.

Factory manifolds were available in low or high-rise and with, spread bore, square bore, tri-power, dual quad, and Fuel Injected configurations. Other than different in port type and deck height all Chevy Big Block Cast Iron intake manifolds are interchangeable from the Mark IV to the Gen VI generations of engines.

If you are sourcing a factory intake manifold for your engine you must start by check the port type. There are 3 different intake port configurations and are not interchangeable. Early Big blocks came with either large Oval or Rectangular ports and Later big blocks also came with smaller Oval Port(Peanut Port) heads.

You will also need to consider if you need a choke stove(early production manifolds) or an EGR port(all manifolds from 1973 on). Production high-rise manifolds were only available up to 1970. From 1971 on all production manifolds were of the low-rise type.

All Chevy Big Block intake manifolds have an identifying Casting number. The number is usually located on one of the intake runners. The number will help determine if you have the correct manifold for your application. A date code is also cast on the manifold and is usually next to the Casting Number. This code is needed when authenticating a matching number car or truck. The Date Code begins with a letter that designates the month of production. A = January B= February and so on. The middle numbers designate the date and the Last number the year.

Example: Date Code F208.
F = June,
20 = 20th Day, and
8 = 1968 or 1978.

Note: The Casting code will help determine the exact year the manifold was cast.

If you can’t find an original exhaust manifold many aftermarket reproductions are available.

3931067 Chey Big Block Cast Iron 4 Barrel Spread Bore Intake Manifold

3963569 Chey Big Block Aluminum 4 Barrel Square Bore Intake Manifold

3894374 Chey Big Block Tri-Power Intake Manifold

3814881 Chey Big Block Dual 4 Barrel Intake Manifold

Big Block Chevrolet Intake Port Types

Big Block Chevrolet Engine Intake Manifold Casting Numbers

Big Block Chevrolet Engine Exhaust Manifolds

Chevrolet used different configurations of Cast Iron exhaust manifold on their Big Block engine. This enabled the engine to be installed on mid-size to full-size cars, trucks, marine, and industrial applications.

All Chevy Big Block Cast Iron exhaust manifolds are interchangeable from the Mark IV to the Gen VI generations of engines. However, clearance issues can arise depending on the chassis or application the engine will be installed in.

All Chevy Big Block engines exhaust manifolds have an identifying Casting number. This number will help find or determine if you have the correct manifold for your application. A date code is also cast on the manifold. This code is helpful when working on the restoration of a matching numbers car or truck.
The Date Code begins with a letter designating the month the manifold was cast. A = January B= February and so on. The middle numbers designate the date and the Last number the year.

Example: Date Code B119

B = February

11 = 11th Day

9 = 1969 or 1979.

Note: the Casting code will help determine the exact year the manifold was cast.

High-performance Big Blocks used manifolds with longer runners. If you’re building a street performance engine and want to use factory manifolds these would be the ones to use.
If you can’t find an original exhaust manifold many aftermarket reproductions are available.

3916178 & 3909879 Chey Big Block LS6 Exhaust Manifold

3969869 & 3880828 Chey Big Block Corvette Exhaust Manifold

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