All Exhaust Systems by Engine Model - Big Block Chevy Mercruiser 496 / 8.1L / 8.2L Exhaust Systems

Seaward Series Replacement 496 Manifolds
Your Price:
$3,299.99

Seaward Series Replacement 496 Manifolds

620-38087

  • Manifold is powder-coated for corrosion protection
  • "Ocean Series" Extreme Corrosion Treatment included for additional interior corrosion protection 
  • 356T Aluminum Heat treated tubular style cast internal manifold core for header like performance
  • Silent choice, captains call, and select sound exhaust diverter system compatible
  • Sold in pairs
  • No tailpipes included, replacement manifolds only!

Seaward Series Big Block Chevy Exhaust System

Starting From:
$3,899.99

This Part has options, please click the button below to order.

Seaward Mercruiser 8.1 / 496MAG and 496MAG HO Replacement Exhaust System

620-3806 + Option(s)

  • Manifold is powder-coated for corrosion protection
  • "Ocean Series" Extreme Corrosion Treatment available for additional interior corrosion protection is standard for 496 system.
  • Designed for use as replacement for OEM Mercruiser 496 manifolds and risers 
  • Polished Stainless steel tailpipe is manufactured from premium 316L Stainless steel, 4" OD 
  • 356T Aluminum Heat treated tubular style cast internal manifold core for header like performance
  • Kit includes all brackets, bolts and gaskets needed for installation
  • 2", 6", and 8" taller versions have 2-3 week lead time for custom tailpipe construction.
  • Check your riser height to make sure you get the correct system.

8.2MAG and 8.2HO Mercruiser NON-Catalyst Exhaust Header System
Your Price:
$6,299.99

This Part has options, please click the button below to order.

8.2MAG and 8.2HO Mercruiser NON-Catalyst Exhaust Header System

650-8200

This new Custom Marine header system was designed as a replacement to the 8.2HO and 8.2MAG ECT catalyst Mercruiser engines with the 2” tall riser on the cast manifold (Which is the most common Mercruiser uses). These risers are easily identifiable by the serial #M82018002 stamped into the riser flange.

The header system is slightly taller than the restrictive factory system due to the improved collector design and down slope. This new header system features a pre-catalyst sensor port provision and NO post cat sensor provision as this header is designed for use with the Cat-Eliminator test system. The headers will connect directly to the factory wet exhaust exhaust hose connection. The header system is available in Satin or Production polished versions. These headers stand 3-1/4" taller than the top of the engine

Note: These headers are not legal for any purpose other than testing purposes and not for use on any state or federal waterway. A PHOTO of your setup must be sent in order to make certain that the correct headers and brackets are built and shipped as there as several versions of this engine package.

CMI 496 E-Top Polished Exhaust Header Systems
Your Price:
$5,999.99

CMI 496 E-Top Polished Exhaust Header Systems

650-13175

CMI 496 E-Top Polished Exhaust Header Systems

How to measure riser height

Direct Mercruiser replacement for your 496 Mag or 496 HO engine. 8-1/2" Stock Riser Height. Polished. No additional custom tails to buy. You don’t need to remove your stock exhaust hose to install this kit, a true plug and play system.

Direct Mercruiser replacement for your 496 Mag or 496 HO engine.

No additional custom tails to buy. You don’t need to remove your stock exhaust hose to install this kit, a true plug and play system.

  • 1 7/8" id primary to get peak horse power and torque.
  • Mandrel bent and formed from High quality 316L grade material.
  • Fully post annealed to reduce stresses built up in the header during the manufacturing process
  • Seamless water jacketed header. No welded inner primaries or water jacketed tubes to crack and leak.
  • More water jacketed protection than your stock exhaust.
  • Approved by Mercruiser to not void warranty on the motor, with the exception of water reversion.
  • Same high quality semi automated welding as used on all racing applications
  • Cool collar patented flange design to eliminate the risk of getting water in the motor by the head flange
  • This kit is price competitive to other aluminum/stainless manifold systems with superior performance and extended life span in harsh marine environments.
  • No cast parts to crack, all CMI collectors are forged from American made stainless steel.
  • Works on 34.5" drive centers
  • Brings a race look to your stock engine.
  • Sophisticated engineering leaves your stock oil lines in place and only requires relocating your oil filter with a supplied bracket.
  • Step by step, do it yourself instructions using Mercury supplied engine schematics.
  • Exhaust Water Temperature Bungs Installed as Standard Equipment.
ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 3-4 WEEKS

CMI 496 E-Top Tall Polished Exhaust Header System, 2" Taller
Your Price:
$6,699.99

CMI 496 E-Top Polished Exhaust System, 2" Taller

650-13177

CMI 496 E-Top Tall Polished Exhaust Header System, 2" Taller

How to measure riser height

Direct Mercruiser replacement for your 496 Mag or 496 HO engine. 10-1/2" Stock Tall Riser Height. Polished. No additional custom tails to buy. You don’t need to remove your stock exhaust hose to install our kit, a true plug and play system.

Direct Mercruiser replacement for your 496 Mag or 496 HO engine.

No additional custom tails to buy. You don’t need to remove your stock exhaust hose to install this kit, a true plug and play system.

  • 1 7/8" id primary to get peak horse power and torque.
  • Mandrel bent and formed from High quality 316L grade material.
  • Fully post annealed to reduce stresses built up in the header during the manufacturing process
  • Seamless water jacketed header. No welded inner primaries or water jacketed tubes to crack and leak.
  • More water jacketed protection than your stock exhaust.
  • Approved by Mercruiser to not void warranty on the motor, with the exception of water reversion.
  • Same high quality semi automated welding as used on all racing applications
  • Cool collar patented flange design to eliminate the risk of getting water in the motor by the head flange
  • This kit is price competitive to other aluminum/stainless manifold systems with superior performance and extended life span in harsh marine environments.
  • No cast parts to crack, all CMI collectors are forged from American made stainless steel.
  • Works on 34.5" drive centers
  • Brings a race look to your stock engine.
  • Sophisticated engineering leaves your stock oil lines in place and only requires relocating your oil filter with a supplied bracket.
  • Step by step, do it yourself instructions using Mercury supplied engine schematics.
  • Exhaust Water Temperature Bungs Installed as Standard Equipment.
ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 3-4 WEEKS

CMI 496 E-Top Satin Exhaust Header Systems
Your Price:
$5,150.99

CMI 496 E-Top Satin Exhaust Header Systems

650-13176

CMI 496 E-Top Satin Exhaust Header Systems

How to measure riser height

Direct Mercruiser replacement for your 496 Mag or 496 HO engine. 8-1/2" Stock Riser Height. Polished. No additional custom tails to buy. You don’t need to remove your stock exhaust hose to install this kit, a true plug and play system.

Direct Mercruiser replacement for your 496 Mag or 496 HO engine.

No additional custom tails to buy. You don’t need to remove your stock exhaust hose to install this kit, a true plug and play system.

  • 1 7/8" id primary to get peak horse power and torque.
  • Mandrel bent and formed from High quality 316L grade material.
  • Fully post annealed to reduce stresses built up in the header during the manufacturing process
  • Seamless water jacketed header. No welded inner primaries or water jacketed tubes to crack and leak.
  • More water jacketed protection than your stock exhaust.
  • Approved by Mercruiser to not void warranty on the motor, with the exception of water reversion.
  • Same high quality semi automated welding as used on all racing applications
  • Cool collar patented flange design to eliminate the risk of getting water in the motor by the head flange
  • This kit is price competitive to other aluminum/stainless manifold systems with superior performance and extended life span in harsh marine environments.
  • No cast parts to crack, all CMI collectors are forged from American made stainless steel.
  • Works on 34.5" drive centers
  • Brings a race look to your stock engine.
  • Sophisticated engineering leaves your stock oil lines in place and only requires relocating your oil filter with a supplied bracket.
  • Step by step, do it yourself instructions using Mercury supplied engine schematics.
  • Exhaust Water Temperature Bungs Installed as Standard Equipment.
ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 3-4 WEEKS

CMI 496 Sport Tube Exhaust System
Your Price:
$7,999.99

CMI 496 Sport Tube Exhaust System

650-13169

CMI 496 Sport Tube Exhaust System

The CMI 496 Sport Tube Performance Package delivers improved performance across the entire operating range of any 496 engine package. When applied to a stock 496 engine, this package will help to increase horsepower, boost mid-range torque, improve fuel economy across the power curve and enhance the engine's overall running quality. The package comes complete with all required mounting hardware plus CMI's exclusive 496 Relocation Kit, which includes all brackets, hoses and hardware needed to make relocation of select engine components easier.

Note: All CMI Systems are sold without Tailpipes

ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 3-4 WEEKS

CMI 496 Sport Tube Internal Sound Choice Exhaust System
Your Price:
$11,349.99

CMI 496 Sport Tube Internal Sound Choice Exhaust System

650-13167

CMI 496 Sport Tube Internal Sound Choice Exhaust System

The CMI 496 Sport Tube Performance Package delivers improved performance across the entire operating range of any 496 engine package. When applied to a stock 496 engine, this package will help to increase horsepower, boost mid-range torque, improve fuel economy across the power curve and enhance the engine's overall running quality. The package comes complete with all required mounting hardware plus CMI's exclusive 496 Relocation Kit, which includes all brackets, hoses and hardware needed to make relocation of select engine components easier.

Includes Pneumatic Pump Kit for Internal Sound Choice

Note: All CMI Systems are sold without Tailpipes

ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 3-4 WEEKS


CMI 496 Sport Tube Straight Pipe Exhaust System
Your Price:
$8,249.99

CMI 496 Sport Tube Straight Pipe Exhaust System

650-13162

CMI 496 Sport Tube Straight Pipe Exhaust System

The CMI 496 Sport Tube Performance Package delivers improved performance across the entire operating range of any 496 engine package. When applied to a stock 496 engine, this package will help to increase horsepower, boost mid-range torque, improve fuel economy across the power curve and enhance the engine's overall running quality. The package comes complete with all required mounting hardware plus CMI's exclusive 496 Relocation Kit, which includes all brackets, hoses and hardware needed to make relocation of select engine components easier.

Note: All CMI Systems are sold without Tailpipes
ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 3-4 WEEKS


Standard Jacketed Header - 496 8.1L Mercury 37" Wide
Starting From:
$3,859.99

This Part has options, please click the button below to order.

Lightning 496 8.1L Mercury 37" Wide Freshwater Headers

310-40 + Option(s)

  • Replacement for Mercury 496 Manifolds
  • For Freshwater Applications
  • Comes complete with bolts, gaskets, water fittings.
  • Includes Shift and oil filter bracket
  • 2" Primary Tube
  • 37" Wide, see specs for detailed measurements
  • See Additional info for more details on Lightning Headers
  • NOTE ALL LIGHTNING HEADERS ARE BUILT TO ORDER IN 4-6 WEEKS