Sanderson Headers C12AC-134-BEC Small Block Chevy Full Length

C12AC-134-BEC Header Set, Small Block Chevy, Chevelle and El Camino

The C12AC-134 is a full-length, 1-3/4″ primary tube header for performance engines in 1964-up Chevrolet Chevelle, Malibu, Monte Carlo, and El Camino (GM A-Body) applications. The “AC” in the part number indicates this version is specifically configured to clear factory air conditioning setups in 1968–72 applications, which require a unique passenger-side header layout.

This full-length design provides easier exhaust routing compared to shorter block hugger styles and is compatible with both straight and angle plug cylinder heads.

1. Fits straight and angle plug cylinder heads
2. Please state if you are using Vortec-style cylinder heads (review information tab)
3. Available with a special D-port flange for D-port cylinder heads (GM ZZ4, ZZ6, 90s LT-1, etc.)
4. Choose either 1-5/8″ or 1-3/4″ primary tube diameter
5. AC-specific version required for factory A/C vehicles in 1968–72

SPECIFICATIONS:

• Engine: Small Block Chevy 265-400
• Primary Tube Diameter: 1-3/4″
• Collector Diameter: 3.0″

FEATURES:

• 16-Gauge Primary and Collector Tube Thickness
• 3/8″ Thick Flange
• Patented Flange Design Requires NO Gaskets
• Tightest Fitting Header Available Anywhere!
• Made in the USA

INCLUDES:

• Header Bolt Set
• Collector Reducer Set

FINISH:

Our Ceramic Coating is recommended for every vehicle application and is the default finish selection choice above. We apply a multi-layer inside-and-out aluminized ceramic coating in-house and polish it to a high luster. This aerospace and military-grade technology provides excellent heat protection, enhances cylinder scavenging, and increases the durability of your headers.

What is a D-Port?

We often see confusion in what is considered a D-Port cylinder head for small block Chevrolet engine applications. The problem originates in the technical understanding of what constitutes a true D-PORT versus a D-shape. The D-Port roof extends well above the centerline of the exhaust port, whereas the D-shaped port fits nicely inside what is deemed a standard port dimension. As shown in the graphic below, the d-shape easily fits within the common round or square port flange opening.

Where other header manufacturers use a typical flat header flange and gasket for sealing, the patented raised flange design of the Sanderson Headers requires different flanges for different small block Chevy exhaust port shapes. Other header flanges will often block the top of the exhaust port on D-port heads. When using a Sanderson D-Port flange the port is not blocked. However, using the wrong flange with a Sanderson header may expose open areas that will not seal, creating an exhaust leak.

Examples:

1. Using a D-port flange on a common GM head (standard round, square, or D-shaped port), the header port flange open is larger (taller opening) than the sealing area around the exhaust port (additional details below, comparing two BRODIX Track 1® cylinder heads)
2. Using a standard Sanderson header flange on a D-port cylinder head has a similar problem, where the cylinder head exhaust port opening may extend above the raised flange sealing area, again creating the possibility of an exhaust leak.

Here is an example of a small block Chevrolet D-port cylinder head that requires the Sanderson D-Port header flange.

WARRANTY:

Limited 5-Year

Sanderson Street Rod Headers warrants this product against defects in materials or workmanship for five years from the date of purchase. Warranty activation requires the return of the enclosed warranty card.

Warranty excludes failures due to improper installation, motor tuning, misuse, damage, or use of thermal wraps. Labor, removal, or shipping costs are not covered.