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

• 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!

• 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.

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.

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.

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.

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

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

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

• 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