LS Engine Parts and Accessories - Exhaust Systems and Accessories

Seaward Series "Alpha/Bravo" LS Chevrolet Exhaust System

Starting From:
$2,199.99

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

Seaward Series "Alpha/Bravo" LS Chevrolet Exhaust System

620-38152 + Option(s)

  • Manifold is powder-coated for corrosion protection
  • Optional "Ocean Series" Extreme Corrosion Treatment available for additional interior corrosion protection 
  • Perfect for use on OEM engines 4.8 to 6.2L up to 400HP (Camshaft duration not to exceed 218 degrees @.050 Duration) 
  • Polished Stainless steel tailpipe is manufactured from premium 316L Stainless steel, 4" OD 
  • 356T Cast Aluminum Heat treated tubular tuned runner header style internal manifold core for header like performance 
  • Drawformed Non-porous manifold shells are powder-coated for corrosion protection
  • Silent choice, captains call, and select sound exhaust diverter system compatible
  • Risers include O2 Sensor bungs and plugs.
  • Kit includes all bolts and gaskets needed for installation

Seaward Series "Alpha/Bravo HP" LS Chevrolet Exhaust System

Starting From:
$3,599.95

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

Seaward Series "Alpha/Bravo HP" LS Chevrolet Exhaust System

620-38153 + Option(s)

  • Manifolds are powder-coated for corrosion protection
  • Optional "Ocean Series" Extreme Corrosion Treatment available for additional interior corrosion protection 
  • Perfect for use on OEM engines 4.8 to 6.2L up to 500HP (Camshaft duration not to exceed 234 degrees @.050 Duration) 
  • Polished Stainless steel tailpipe is manufactured from premium 316L Stainless steel, 4" OD 
  • 356T Cast Aluminum Heat treated tubular tuned runner header style internal manifold core for header like performance 
  • Drawformed Non-porous manifold shells are powder-coated for corrosion protection
  • Silent choice, captains call, and select sound exhaust diverter system compatible
  • High Performance Risers include O2 Sensor bungs and plugs.
  • Kit includes all bolts and gaskets needed for installation

Seaward Series "Alpha/Bravo XL" LS Chevrolet Exhaust System

Starting From:
$2,399.99

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

Seaward Series "Alpha/Bravo XL" LS Chevrolet Exhaust System

620-38156 + Option(s)

  • Manifolds are powder-coated for corrosion protection
  • Optional "Ocean Series" Extreme Corrosion Treatment available for additional interior corrosion protection 
  • Perfect for use on OEM engines 4.8 to 6.2L up to 435HP (Camshaft duration not to exceed 228 degrees @.050 Duration) 
  • Polished Stainless steel tailpipe is manufactured from premium 316L Stainless steel, 4" OD 
  • 356T Cast Aluminum Heat treated tubular tuned runner header style internal manifold core for header like performance 
  • Drawformed Non-porous manifold shells are powder-coated for corrosion protection
  • Silent choice, captains call, and select sound exhaust diverter system compatible
  • XL Risers include O2 Sensor bungs and plugs.
  • Kit includes all bolts and gaskets needed for installation

Seaward Series "Jet Boat" LS Chevrolet Exhaust System

Starting From:
$2,399.99

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

Seaward Series "Jet Boat" LS Chevrolet Exhaust System

620-38154 + Option(s)

  • Manifolds are powder-coated for corrosion protection
  • Optional "Ocean Series" Extreme Corrosion Treatment available for additional interior corrosion protection 
  • Perfect for use on OEM engines 4.8 to 6.2L up to 425HP (Camshaft duration not to exceed 224 degrees @.050 Duration) 
  • Polished Stainless steel tailpipe is manufactured from premium 316L Stainless steel, 4" OD 
  • 356T Cast Aluminum Heat treated tubular tuned runner header style internal manifold core for header like performance 
  • Drawformed Non-porous manifold shells are powder-coated for corrosion protection
  • These Lower Exit Risers are perfect for many inboard ski/wake or Jet Boat applications requiring additional exhaust exit downslope
  • Include O2 Sensor bungs and plugs
  • Kit includes all bolts and gaskets needed for installation

Seaward Series "Alpha/Bravo Low Exit" LS Chevrolet Exhaust System

Starting From:
$3,499.99

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

Seaward Series "Alpha/Bravo Low Exit" LS Chevrolet Exhaust System

620-38155 + Option(s)

  • Manifold is powder-coated for corrosion protection
  • Optional "Ocean Series" Extreme Corrosion Treatment available for additional interior corrosion protection 
  • Perfect for use on OEM engines 4.8 to 6.2L up to 400HP (Camshaft duration not to exceed 218 degrees @.050 Duration) 
  • Polished Stainless steel tailpipe is manufactured from premium 316L Stainless steel, 4" OD 
  • 356T Cast Aluminum Heat treated tubular tuned runner header style internal manifold core for header like performance 
  • Drawformed Non-porous manifold shells are powder-coated for corrosion protection
  • Silent choice, captains call, and select sound exhaust diverter system compatible
  • Low Exit Risers include O2 Sensor bungs and plugs.
  • Kit includes all bolts and gaskets needed for installation

Cyclone Header System For GM Big Block Standard Dimension Bravo
Your Price:
$5,299.99

Cyclone Header System For GM LS Standard Bravo Tailpipes

620-32570

Cyclone Water Jacketed Header System For GM LS and Standard Dimension Bravo - Fully Polished - Pair of Headers for one engine.

This new cyclone header system is designed specifically for GM LS engines. The tailpipes are set up for standard Bravo exit locations.

This Cyclone wet exhaust series header works perfectly on both stock and modified performance applications This header mixes engine cooling water with the exhaust near the end of the tailpipe That allows you to use a 4" rubber hose connection to attach your transom mounted exhaust tips This is the perfect replacement for your factory exhaust system.  Gaskets, and bolts included.

If you are one of thousands of performance boaters oseeking the power and styling from stainless steel tubular headers then you're looking at the leader in exhaust technology These "Cyclone" header systems share 100% 316L stainless steel construction. All appropriate flanges are laser cut and CNC machined for a perfect gasket seal. Each individual exhaust tube is bent to precise, exact tolerances every time. A computer designed fully welded water inlet manifold provides equal water distribution to each exhaust runner tube. While each set of headers goes through a 1900 degree annealing process that multiplies the durability factor of the header many times over while providing added protection against corrosion. But the heart of these systems lies in the ability to generate loads of additional power. By using CAD-5 Technology to develop a unique staggered tube runner length, these systems are capable of maximizing the broadest low end and midrange torque, all the while yielding incredible peak power gains. These systems are available in many configurations to fit every boaters needs. Rest assured when you lay down your hard earned money because the system comes complete with all necessary mounting bolts, gaskets, and shift and oil filter brackets making installation a snap. This kit includes one (1) O2 bung standard, if you need a 2nd O2 bung on your kit, see related parts below.

Additional Information:


Cyclone Header System For GM Big Block Standard Dimension Bravo
Your Price:
$4,199.99

Cyclone Header System For GM LS with Turbo Adapter Flange

620-32560

Cyclone Water Jacketed Header System For GM LS with Turbo Adapter Flange  - Fully Polished - Pair of Headers for one engine.

This new cyclone header system is designed specifically for GM LS engines. The header has an adapter flange set up to easily adapt a turbo for use with the system.

This Cyclone wet exhaust series header works perfectly on both stock and modified performance applications This header mixes engine cooling water with the exhaust near the end of the tailpipe That allows you to use a 4" rubber hose connection to attach your transom mounted exhaust tips This is the perfect replacement for your factory exhaust system. Gaskets, and bolts included.

If you are one of thousands of performance boaters seeking the power and styling from stainless steel tubular headers then you're looking at the leader in exhaust technology These "Cyclone" header systems share 100% 316L stainless steel construction. All appropriate flanges are laser cut and CNC machined for a perfect gasket seal. Each individual exhaust tube is bent to precise, exact tolerances every time. A computer designed fully welded water inlet manifold provides equal water distribution to each exhaust runner tube. While each set of headers goes through a 1900 degree annealing process that multiplies the durability factor of the header many times over while providing added protection against corrosion. But the heart of these systems lies in the ability to generate loads of additional power. By using CAD-5 Technology to develop a unique staggered tube runner length, these systems are capable of maximizing the broadest low end and midrange torque, all the while yielding incredible peak power gains. These systems are available in many configurations to fit every boaters needs. Rest assured when you lay down your hard earned money because the system comes complete with all necessary mounting bolts, gaskets, and shift and oil filter brackets making installation a snap.

Additional Information:


CMI LS Chevy E-Top Headers
Starting From:
$4,724.99

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

CMI LS Chevy E-Top Headers

650-1320 + Option(s)

CMI CMI LS Chevy E-Top Headers, Polished or Satin Finish

  • Improved exhaust flow over existing cast manifolds
  • Lightweight 316L stainless steel
  • Increased fuel efficiency
  • Inside port size of 1-5/8", also in 1-7 /8"
  • Smooth mandrel bent tubes
  • No separate tailpipe required
  • Taller custom application options

Note: All CMI Systems are sold without Tailpipes

ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 7-8 MONTHS

Imco Powerflow LS Chevy Kit with Cast Black Riser and Black Manifolds
Your Price:
$1,999.99

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

Imco Powerflow LS Chevy Kit with Cast Black Riser and Black Manifolds

421-02-8383

Imco Powerflow LS Chevy Kit with Cast Black Riser and Black Manifolds

This system has a 10% horsepower increase and 40-50 foot pounds of torque on stock engines. All Powerflow systems are available fully polished.

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

 The outside manifold surfaces are then coated with the highest quality epoxy powder coating available, creating a part that not only is highly corrosion resistant, but good looking as well. Features an external fitting to accept stock MerCruiser thermostat plumbing.

NOTE: NO O2 PROVISION

This exhaust system will not work with Hardin Marine Accessory Drive Kits 625-8312 and 625-8313 and closed cooling kit 625-8574.


Imco Powerflow LS Chevy Kit with Cast Polished Riser and Polished Manifolds
Your Price:
$2,199.99

Imco Powerflow LS Chevy Kit with Cast Polished Riser and Polished Manifolds

421-02-8385

Imco Powerflow LS Chevy Kit with Cast Polished Riser and Polished  Manifolds

This system has a 10% horsepower increase and 40-50 foot pounds of torque on stock engines. All Powerflow systems are available fully polished.

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

 The outside manifold surfaces are then coated with the highest quality epoxy powder coating available, creating a part that not only is highly corrosion resistant, but good looking as well. Features an external fitting to accept stock MerCruiser thermostat plumbing.

NOTE: NO O2 PROVISION

This exhaust system will not work with Hardin Marine Accessory Drive Kits 625-8312 and 625-8313 and closed cooling kit 625-8574.


Imco Powerflow LS Chevy Kit with Stainless Riser and Black Manifolds
Your Price:
$2,828.99

Imco Powerflow LS Chevy Kit with Stainless Riser and Black Manifolds

421-02-8382

Imco Powerflow LS Chevy Kit with Stainless Riser and Black Manifolds

This "A" pipe is used with Bravo drives or King Cobra drives. It's short design allows for thru transom exhaust tip hook-up. This system has a 10% horsepower increase and 40-50 foot pounds of torque on stock engines. All Powerflow systems are available fully polished.

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

 The outside manifold surfaces are then coated with the highest quality epoxy powder coating available, creating a part that not only is highly corrosion resistant, but good looking as well. Features an external fitting to accept stock MerCruiser thermostat plumbing. O2 Sensor Provision Option Available.


Imco Powerflow LS Chevy Kit with Stainless Riser and Polished Manifolds
Your Price:
$2,899.99

Imco Powerflow LS Chevy Kit with Stainless Riser and Polished Manifolds

421-02-8384

Imco Powerflow LS Chevy Kit with Stainless Riser and Polished Manifolds

This "A" pipe is used with Bravo drives or King Cobra drives. It's short design allows for thru transom exhaust tip hook-up. This system has a 10% horsepower increase and 40-50 foot pounds of torque on stock engines. All Powerflow systems are available fully polished.

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

 The outside manifold surfaces are then coated with the highest quality epoxy powder coating available, creating a part that not only is highly corrosion resistant, but good looking as well. Features an external fitting to accept stock MerCruiser thermostat plumbing.  O2 Sensor provision option available.

This exhaust system will not work with Hardin Marine Accessory Drive Kits 625-8312 and 625-8313 and closed cooling kit 625-8574.


Standard Jacketed Header - S/B Chevy 350 Mercury 31" Wide
Starting From:
$3,589.99

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

Lightning GM LS 4.8, 5.3, 6.0, 6.2, 7.0L Fresh Water Jet Headers

310-40 + Option(s)

Standard Jacketed Header - S/B Chevy LS1 Jet Boat

These headers are designed to be a replacement for Mercury, OMC or jet manifolds. However, they terminate approximately 8" aft of stock manifolds and are projected to meet the exhaust tips providing they are in the stock location. Headers will have about 1/2" clearance between header and tall Moroso valve covers. Headers come complete with bolts, gaskets, waterfittings, pet cocks, etc. (less 4" hose and 4" hose clamps). Factory oil filter requires relocation.

LIGHTNING PERFORMANCE
When comparing performance exhaust systems it's good to understand the different systems on the market today and the performance demands of your engine. Understanding how a header works will help you decide on which exhaust system is best suited for your application.

Headers have two basic functions. First is to simply relieve back pressure. For example, when looking at a manifold you see a 4" diameter exhaust hose, but the actual exhaust gas opening is about 2-1/2" diameter. Most performance manifolds and some header manufacturers use a 4" exhaust hose and 3" or 3-1/2" OD exhaust gas tube. All of these headers use a 4" OD exhaust gas tube and a 5" water jacket tube until the water gets introduced into the exhaust gas stream, then it gets reduced from 5" to its 4" exhaust hose diameter. At no time does the exhaust gases see a diameter smaller than 4" OD. When looking at these exhaust gas openings consider their area not their diameter. For example, a 4" OD opening has an area of approximately 12.56 sq. in. A 3-1/2" opening has an area of approximately 9.62 sq. in.That is 25% smaller! A 3" opening is approximately 7.06 sq. in. and a 2-1/2" opening is approximately 4.90 sq. in. which is 60% smaller.

LIGHTNING HORSE POWER COMPARISON
Performance figures on headers vary considerably. As a rule, the higher horsepower engines benefit more than the lower horsepower engines. For example, the 330hp Mercury engine will gain approximately 50 to 75 rpm, where as the 365 hp Mercury engine will gain approximately 300 to 400 rpm (45 hp). Blown engines gain up to 800 rpm (80 hp). Of course this is comparing these headers against stock Mercury center rise manifolds.

LIGHTNING CONSTRUCTION
Our Magnum header starts with Mandrel bent 316L stainless steel interior tubes. The exterior tubes are Mandrel bent heavy wall steel tube (.074). The tubes are then mechanically etched by sand blasting and then assembled. Finally, a corrosion resistant silicone ceramic coating is applied to the interior of the header while the exterior receives a powder coat finish.

ALL THIS PLUS THE BEST 2-YEAR WARRANTY IN THE INDUSTRY

Through continuing research Lightning Mfg. has developed a Dual Porcelain Coating that resists the harshest of salt water environments. Now as an option theyare able to apply the same high tech coating to a 316L stainless steel lined header once thought to be the cracking alloy and render it crack resistant.

NOTE: LIGHTNING HEADERS HAVE A 4-6 WEEKS BUILD TIME.


Standard Jacketed Header - S/B Chevy 350 Mercury 31" Wide
Starting From:
$3,459.99

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

Lightning GM LS 4.8, 5.3, 6.0, 6.2, 7.0L Fresh Water Mercury Bravo Headers

310-40 + Option(s)

Standard Jacketed Header - S/B Chevy LS1 Mercury

These headers are designed to be a replacement for Mercury, OMC or jet manifolds. However, they terminate approximately 8" aft of stock manifolds and are projected to meet the exhaust tips providing they are in the stock location. Headers will have about 1/2" clearance between header and tall Moroso valve covers. Headers come complete with bolts, gaskets, waterfittings, pet cocks, etc. (less 4" hose and 4" hose clamps). Factory oil filter requires relocation.

LIGHTNING PERFORMANCE
When comparing performance exhaust systems it's good to understand the different systems on the market today and the performance demands of your engine. Understanding how a header works will help you decide on which exhaust system is best suited for your application.

Headers have two basic functions. First is to simply relieve back pressure. For example, when looking at a manifold you see a 4" diameter exhaust hose, but the actual exhaust gas opening is about 2-1/2" diameter. Most performance manifolds and some header manufacturers use a 4" exhaust hose and 3" or 3-1/2" OD exhaust gas tube. All of these headers use a 4" OD exhaust gas tube and a 5" water jacket tube until the water gets introduced into the exhaust gas stream, then it gets reduced from 5" to its 4" exhaust hose diameter. At no time does the exhaust gases see a diameter smaller than 4" OD. When looking at these exhaust gas openings consider their area not their diameter. For example, a 4" OD opening has an area of approximately 12.56 sq. in. A 3-1/2" opening has an area of approximately 9.62 sq. in.That is 25% smaller! A 3" opening is approximately 7.06 sq. in. and a 2-1/2" opening is approximately 4.90 sq. in. which is 60% smaller.

LIGHTNING HORSE POWER COMPARISON
Performance figures on headers vary considerably. As a rule, the higher horsepower engines benefit more than the lower horsepower engines. For example, the 330hp Mercury engine will gain approximately 50 to 75 rpm, where as the 365 hp Mercury engine will gain approximately 300 to 400 rpm (45 hp). Blown engines gain up to 800 rpm (80 hp). Of course this is comparing these headers against stock Mercury center rise manifolds.

LIGHTNING CONSTRUCTION
Our Magnum header starts with Mandrel bent 316L stainless steel interior tubes. The exterior tubes are Mandrel bent heavy wall steel tube (.074). The tubes are then mechanically etched by sand blasting and then assembled. Finally, a corrosion resistant silicone ceramic coating is applied to the interior of the header while the exterior receives a powder coat finish.

ALL THIS PLUS THE BEST 2-YEAR WARRANTY IN THE INDUSTRY

Through continuing research Lightning Mfg. has developed a Dual Porcelain Coating that resists the harshest of salt water environments. Now as an option theyare able to apply the same high tech coating to a 316L stainless steel lined header once thought to be the cracking alloy and render it crack resistant.

NOTE: LIGHTNING HEADERS HAVE A 4-6 WEEKS BUILD TIME.


LS1 Small Block Chevy Exhaust System
Your Price:
$59.99

Shift Bracket for LS Marine Aluminum Exhaust Manifold System

620-32492

Shift Bracket for LS Marine Aluminum Exhaust Manifold System

Add an Shift bracket to the 620-32940 or 620-32942 LS Exhaust Systems or IMCO LS Exhaust Systems.


LS1 Small Block Chevy Exhaust System
Your Price:
$59.99

ECM Bracket for LT Marine Aluminum Exhaust Manifold System

620-32490

ECM Bracket for LT Marine Aluminum Exhaust Manifold System

Add a ECM bracket to the 620-32940 or 620-32942 LT Exhaust Systems or IMCO LT Exhaust Systems.

NOTE: If using with a riser mounted O2 Sensor, modification to bracket will be required or O2 sensor moved inboard.


LS1 Small Block Chevy Exhaust System
Your Price:
$200.00

Extra O2 Bung for LS Marine Aluminum Exhaust Manifold System

620-32941

Extra O2 Bung for LS Marine Aluminum Exhaust Manifold System

The 620-32940 Exhaust System comes with a single O2 Bung, however some systems require a 2nd O2 bung. Order this part alongside a 620-32940 system to have two O2 bungs.


LS1 Small Block Chevy Exhaust System
Your Price:
$10.99

Riser Gasket for LS Marine Aluminum Exhaust Manifold System

620-32494

Replacement Riser Gasket for LS Marine Aluminum Exhaust Manifold System

Replacement Riser Gasket for the 620-32940 or 620-32942 LS Exhaust Systems or IMCO LS Exhaust Systems.


LS1 Small Block Chevy Exhaust System
Your Price:
$32.99

Exhaust Gaskets for LS Marine Aluminum Exhaust Manifold System

620-32496

Exhaust Gaskets for LS Marine Aluminum Exhaust Manifold System

Replacement Exhaust Gaskets for the 620-32940 or 620-32942 LS Exhaust Systems or IMCO LS Exhaust Systems. Sold in pairs for one engine.


GM Gen III/IV Small Block V8. LS Series .030" MLS Exhaust Gaskets.
Your Price:
$37.58

GM Gen III/IV Small Block V8. LS Series .030" MLS Exhaust Gaskets.

302-C5818-030

GM Gen III/IV Small Block V8. LS Series .030" MLS Exhaust Gaskets. - Sold in Pairs

The Cometic Severe Duty Multi Layer Series exhaust gaskets are comprised of three separate layers of stainless steel. Cometic uses stainless steel for increased strength and its ability to rebound from heat compression, plus excellent corrosion resistance. The outer layers of the gasket are embossed and coated. This is designed to meet the demands of a variety of harsh sealing environments, load conditions and surface finishes.

The Severe Duty MLS exhaust gasket is ideal for both aluminum heads & cast iron heads as well as cast iron and aluminum blocks. The composition of MLS gaskets will also withstand the shearing forces created by aluminum heads on cast iron blocks. No re-torque is required and by design promotes an even torque load across the sealing surface.

Sold in Pairs


LS Exhaust Gasket
Your Price:
$34.99

LS Exhaust Gasket

650-34015

LS Exhaust Gasket

Sold Each


Closed Sealing Tube for LS Exhaust Manifolds
Your Price:
$23.99

Closed Sealing Tube for LS Exhaust Manifolds

620-32947

Closed Sealing Tube for LS Exhaust Manifolds. Used in Closed Cooling applications.

Open Sealing Tube for LS Exhaust Manifolds
Your Price:
$23.99

Open Sealing Tube for LS Exhaust Manifolds

620-32943

Open Sealing Tube for LS Exhaust Manifolds.