Custom Marine Inc. - Big Block Chevy Headers

CMI Big Block Chevy Standard Bravo Sport Tube Exhaust System, Polished

CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big- and small-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Sport Tube Exhaust System, 6" Taller, Polished

CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big- and small-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Sport Tube Exhaust System, 6" Taller, Leaned , Polished

CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big- and small-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation. Leaned for Staggered Engine Applications.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Sport Tube Exhaust System, 9" Taller, Polished

CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big- and small-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Sport Tube Exhaust System, 11" Taller, Polished

CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big- and small-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Sport Tube Exhaust System, 11" Taller,  Leaned, Polished

CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big- and small-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement. Leaned for Staggered engine applications.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-1/4" Primaries, Polished

These “Big Tubes” offer a large 2.25″ primary, straight back superior long tube header designed for both racing or any high-performance application. These straight, taller headers are commonly used in custom high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tubes headers deliver peak performance and power from naturally aspirated engines. The headers can be built to your custom measurements based on your motor.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-1/8" Primaries, Polished

These “Big Tubes” offer a large 2 1/8″ primary, straight back superior long tube header designed for both racing or any high-performance application. These leaned, taller headers are commonly used in custom high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tube headers deliver peak performance and power from naturally aspirated engines. This is a full polished header.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-1/8" Primaries, 850-1200 SC Flange, Polished

These “Big Tubes” offer a large 2 1/8″ primary, straight back superior long tube header designed for both racing or any high-performance application. They feature a “D” Port flange to match the Brodix heads on Mercury 850-1200 SC motors. These leaned, taller headers are commonly used in custom or staggered set up for your high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tube headers deliver peak performance and power from naturally aspirated engines. This is a full polished header.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-1/8" x 2-1/4", Stepped Primaries, Polished

These “Big Tubes” offer a large 2-1/8" x 2-1/4" Stepped primary, straight back superior long tube header designed for both racing or any high-performance application. These straight, taller headers are commonly used in custom high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tubes headers deliver peak performance and power from naturally aspirated engines. The headers can be built to your custom measurements based on your motor.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-3/8" Primaries, Polished

These “Big Tubes” offer a large 2 3/8″ primary, straight back superior long tube header designed for both racing or any high-performance application. These leaned, taller headers are commonly used in custom high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tube headers deliver peak performance and power from naturally aspirated engines. This is a full polished header.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Standard Bravo Sport Tube Exhaust System, Polished, Downturned, Swept Back

CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big- and small-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

The all polished CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement.

The all polished CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement. This version is leaned for use on staggered engine applications.

The all polished 3″ taller CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement. These particular headers are commonly used in staggered forward engine applications.

The all polished 3″ taller CMI Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement. These particular headers are commonly used in staggered forward engine applications. Leaned for Staggered engine applications.

The all polished 6″ taller CMI Special Sweep Sport Tubes are commonly used in custom or staggered installations. Custom Marine Sport Tubes are a superior long tube header designed for both racing or virtually any high-performance application. For big-block applications where maximum scavenging and horsepower are required, CMI Sport Tube headers deliver peak performance and power from naturally aspirated engines that generate more than one horsepower per cubic inch of displacement. These particular headers are commonly used in staggered and forward engine applications. 

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-1/4" Primaries, 18"T x 26.25"W, Polished

These “Big Tubes” offer a large 2.25″ primary, straight back superior long tube header designed for both racing or any high-performance application. These straight back, taller headers are commonly used in custom high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tube headers deliver peak performance and power from naturally aspirated engines. The headers are built with a collector width of 26.25” center to center and a collector height from the crankshaft of 18”.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-1/4" Primaries, 21.5"T x 28"W, Polished

These “Big Tubes” offer a large 2.25″ primary, straight back superior long tube header designed for both racing or any high-performance application. These straight back, taller headers are commonly used in custom high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tube headers deliver peak performance and power from naturally aspirated engines. The headers are built with a collector width of 28” center to center and a collector height from the crankshaft of 21 ½”.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-1/4" Primaries, 24.5"T x 28"W, Polished

These “Big Tubes” offer a large 2.25″ primary, straight back superior long tube header designed for both racing or any high-performance application. These straight back, taller headers are commonly used in custom high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tube headers deliver peak performance and power from naturally aspirated engines. The headers are built with a collector width of 28” center to center and a collector height from the crankshaft of 24 ½”.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-1/4" Primaries, 27.5"T x 25"W, Polished

These “Big Tubes” offer a large 2.25″ primary, straight back superior long tube header designed for both racing or any high-performance application. These straight back, taller headers are commonly used in custom high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tube headers deliver peak performance and power from naturally aspirated engines. The headers are built with a collector width of 25” center to center and a collector height from the crankshaft of 27 ½”.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-1/4" Primaries, Polished, 5 Degree Downturn

These “Big Tubes” offer a large 2.25″ primary, straight back superior long tube header designed for both racing or any high-performance application. These straight, taller headers are commonly used in custom high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tubes headers deliver peak performance and power from naturally aspirated engines. The headers can be built to your custom measurements based on your motor.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

CMI Big Block Chevy Big Sport Tube Exhaust System, 2-1/8" Primaries, 18"T x 26.25"W, Polished

These “Big Tubes” offer a large 2.125″ primary, straight back superior long tube header designed for both racing or any high-performance application. These straight back, taller headers are commonly used in custom high horsepower builds. These headers feature the CMI Big Tube Flex Flare Tailpipe Connection. For big-block applications, where maximum scavenging and horsepower are required, CMI Big Tube headers deliver peak performance and power from naturally aspirated engines. The headers are built with a collector width of 26.25” center to center and a collector height from the crankshaft of 18”.

The all polished Sport Tube system is offered with a range of exhaust tailpipe options, as well as CMI's Sound Choice™ selectable silencing system. Each system includes all header attaching bolts, gaskets and cooling fittings required for installation.

Note: All CMI Systems are sold without Tailpipes

Replacement HP 500 CMI Tail Pipes Standard Bravo, Early Model

These are factory replacements HP 500 EFI Tail Pipe replacements for Mercury Flange Header Early Models that have a straight jump hose.

Mercury OEM Part Numbers: 848739A1, 848735A1

Replacement HP 500 EFI Mercury Late Model Tail Pipes with 180° Jump Hose

For Stock Bravo Hole Location

Mercury OEM Numbers: 8M0053624, 845236A1