LS Engine Parts and Accessories - Exhaust Systems and Accessories

• NOTE: THESE SYSTEMS WILL FIRST SHIP MID-MAY 2023. Currently available for PRE-ORDER ONLY!
• 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

GM LT1 / LT4 Aluminum 4" Marine Exhaust System

The NEW Aluminum marine GM LT exhaust manifold systems are a popular option for LT1 / LT4 GM OEM and GM Marine based engine platforms up to 550HP. This system features a single o2 sensor bung provision on one of the exhaust risers (a second is optional).The system features a dry-joint style flange that passes water from the manifold to the flange making closed cooling options simple. The exhaust risers feature a 4" exhaust hose connection standard.

Not for use with engines using a camshaft with more than .224 @ .050 Camshaft Duration. This Exhaust System is sold in a raw Aluminum "As-Cast" satin finish, Installer will be required to apply any final finish as the outside is ROUGH aluminum. sanding, polishing, coating or Painting is the responsibility of the purchaser!

Note: these are sold as a pair. The fit the LT 5 bolt pattern not the LS 6 bolt pattern.

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:

• How To Measure For Custom Tailpipes

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:

• How To Measure For Custom Tailpipes

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

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.

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.

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.

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.

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 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.

NOTE: Custom Lightning Headers are now built to order by quote only. Please select your options below and we will have a price and turn around time quoted to you as soon possible. Please make sure your contact information (e-mail address and phone number) are correct when placing an order for a quote. 

All orders of Lightning Headers will require you to provide measurements, see these diagrams:

Lightning Jet Headers
Lightning Mercury Headers
Lightning Generic Headers

Please select all the options below you wish to have on your headers. By ordering this item you are asking for a quote only. 

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

LS1 Headers, Jet, Long, Chrome

This is the header the Bassett legacy was built on. It's clean smooth flowing shape and high luster chrome are a sure winner anywhere. All original style headers come with gaskets, bolts, tee valve, water injection lines, and hardware.

Sold As A Pair

NOTE: ALL BASSETT HEADERS SHIP SIGNATURE REQUIRED. SOMEONE MUST BE PRESENT TO RECEIVE THE PACKAGE!

LS1, LS, LS3 and LS6 Headers, Jet, Short, Chrome

This is the header the Bassett legacy was built on. It's clean smooth flowing shape and high luster chrome are a sure winner anywhere. All original style headers come with gaskets, bolts, tee valve, water injection lines, and hardware.

Sold As A Pair

NOTE: ALL BASSETT HEADERS SHIP SIGNATURE REQUIRED. SOMEONE MUST BE PRESENT TO RECEIVE THE PACKAGE!

LS1 Headers, V-Drive, Long, Chrome

This is the header the Bassett legacy was built on. It's clean smooth flowing shape and high luster chrome are a sure winner anywhere. All original style headers come with gaskets, bolts, tee valve, water injection lines, and hardware.

Sold As A Pair

NOTE: ALL BASSETT HEADERS SHIP SIGNATURE REQUIRED. SOMEONE MUST BE PRESENT TO RECEIVE THE PACKAGE!

LS1 Headers, V-Drive, Short, Chrome

This is the header the Bassett legacy was built on. It's clean smooth flowing shape and high luster chrome are a sure winner anywhere. All original style headers come with gaskets, bolts, tee valve, water injection lines, and hardware.

Sold As A Pair

NOTE: ALL BASSETT HEADERS SHIP SIGNATURE REQUIRED. SOMEONE MUST BE PRESENT TO RECEIVE THE PACKAGE!

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.

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.

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.

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.

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. - 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

Sold Each