CMI Header Applications

Available Systems

Sign up for the
CMI e-newsletter

Stay up-to-date on new products, promotions and events.


CMI Industrial is proud of its heritage as a designer and manufacturer of top-quality sound and noise attenuation systems that have set the benchmark for quality and innovation. CMI has enjoyed a decades-long leadership position by offering unparalleled products and services, and maintaining industry-leading customer satisfaction.

Visit CMI Industrial

CMI Big Tube™ Systems

CMI Big Tube Header
click to view larger image

CMI Big Tube headers enable big block engines with 540 cubic-inch displacements or more to deliver peak horsepower and torque throughout the entire operating range. CMI Big Tube Headers are proven to withstand one of the toughest marine environments on earth – offshore racing – and have powered more National and World Championship boats than all other brands combined. CMI “Big Tubes” can be custom stepped in any configuration to meet any engine builders’ requirements.

The fully polished CMI Big Tube systems are offered with the largest inside diameter options available on the market, including 2 1/8-, 2 ¼-, and 2 3/8-inch inside diameters for any step combination. CMI offers a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system, to complete any installation. All CMI Big Tube systems include stainless steel cooling fluid distribution tubes, header attaching bolts, all necessary gaskets and cooling fittings required for installation. Tailpipes sold separately.

Best pricing and availability through one of our
CMI Distributors or CMI Authorized here for details.

Part Part Number
Big Block 2.125" I.D., Low Profile
Low profile, 26-1/4" x 18" tall on standard GM head & block.
Big Block 2.125" I.D. 13670
Big Block Chevrolet 2.25" I.D. 13680
Big Block Chevrolet 2.375" I.D. 13720
Ford 460 2.375" I.D. 13815
Ford 460 2.25" I.D. and 2.125 I.D 13825
Stepped I.D. System 13690

Split Top Components

Header Upgrade Garage

  • Brackets
  • Sensor Couplings
  • Header Bolts