How to Choose the Right Size Headers For SBC 406

Headers are an essential part of any high-performance engine, and the SBC 406 is no exception. Choosing the right size headers for your SBC 406 can make all the difference in terms of horsepower, torque, and overall engine performance. With so many different types of headers available, it can be challenging to know which ones are right for your specific engine.

Understanding Headers

right size headers for sbc 406

Headers are exhaust manifolds that are designed to optimize engine performance. They work by increasing exhaust flow and reducing backpressure, which improves horsepower and torque.

  • Long tube headers are typically the best choice for SBC 406 engines, as they provide the most significant increase in power.
  • Short tube headers are a good choice for those looking for a more affordable option, while tri-y headers are best for engines with a broader torque band.

There’s some debate on short vs. long tube headers and the impact on sound.

 One crucial component that should not be overlooked is the camshaft. Camshafts work in conjunction with headers to optimize engine performance, which means that choosing headers that are compatible with your camshaft can have a significant impact on horsepower, torque, and overall responsiveness. Therefore, it is essential to select headers that are designed to work well with your camshaft. By doing so, you can ensure that you are maximizing the performance of your SBC 406 engine and achieving the best possible results. See our guide on the best cams for SBC 406.

Selecting the Right Size Headers for an SBC 406 Engine:

To determine the right size header for an SBC 406 engine, follow these steps:

  1. Measure the primary tube diameter: Using a caliper, measure the inside diameter of the primary tube at the flange.
  2. Calculate the total cross-sectional area: Square the primary tube diameter and multiply it by 0.7854 (π/4).
  3. Determine the engine displacement: Calculate the engine displacement by multiplying the bore (diameter of the cylinder) squared, times the stroke (length of the piston’s travel), times 0.7854 (π/4), times the number of cylinders.
  4. Calculate the ideal primary tube length: Divide the engine displacement by the total cross-sectional area, then multiply the result by 0.95 for a street car or 1.05 for a race car.
  5. Choose the closest available header size: Based on the ideal primary tube length, choose the header size that is closest to the calculated length.

By following these steps, you can determine the correct header size for your SBC 406 engine.

Discover the best long tube headers for 5.3 Silverado

Installation and Maintenance Tips for Headers on SBC 406:

Proper installation is critical when it comes to headers. When installing headers on your SBC 406 engine, it’s important to follow the manufacturer’s instructions carefully. It’s also crucial to keep headers well-maintained to ensure optimal performance. This includes regular cleaning and inspection to prevent rust and other types of corrosion.


Choosing the right size headers for SBC 406 engine is essential for achieving the best possible performance. By understanding the different types of headers available and considering factors such as compatibility, size, and construction, you can select the best headers to meet your engine’s specific needs. With proper installation and maintenance, you can enjoy improved horsepower and torque, as well as better overall engine performance.

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