All Exhaust Systems by Engine Model - Big Block Chevy 454 / 502, 7.4L / 8.2L Exhaust Systems

Big Block Chevy Gil Replacement Custom Dry Offshore System (Tailpipes built to your dimensions)

The dry exhaust system is designed for ultra hi-performance engines, especially those with high overlap cams.  The water jacketed pipes extend through the transom and keep the exhaust gasses dry all the way to the end.  More and more competitive offshore racers are using the Hardin Offshore Dry System.

Hardin Exhaust Systems perform better because they're made better, with great attention to detail in design, engineering and manufacturing.  These manifolds are coated inside and out, proven to protect better than conventional marine coatings.  These exhaust pipes are designed to keep cooling water separated from the exhaust flow to avoid corrosion of valves, rings and pistons.  And these exclusive patented Turbulator Rings have proven themselves in protecting engines against water ingestion due to condensation.

Hardin Exhaust Systems are the overwhelming choice of boaters who want top-end performance with durability.  These exhaust systems deliver by allowing your engine to breathe easier and perform better.  Boaters spend thousands of dollars to modify their engines to increase horsepower and speed.  But, unless the exhaust system is capable of the additional flow required, the modifications are wasted.

These exhaust systems allow center to center engine dimensions of 32-5/16" and are 1-5/8" taller than Mercury cast iron manifolds mounted on stock short decks with GM Heads.

Note:  Pricing indicated includes STANDARD DIMENSION Tailpipes only.  Custom Tailpipes may incur additional charges depending on the length and complexity of the tailpipe required.

Priced according to your dimensions.  Submit your custom measurements for a price quote.

Big Block Chevy Gil Replacement TRS Standard Dry Offshore System

The dry exhaust system is designed for ultra hi-performance engines, especially those with high overlap cams.  The water jacketed pipes extend through the transom and keep the exhaust gasses dry all the way to the end.  More and more competitive offshore racers are using the Hardin Offshore Dry System.

Hardin Exhaust Systems perform better because they're made better, with great attention to detail in design, engineering and manufacturing.  These manifolds are Hardincoated inside and out, proven to protect better than conventional marine coatings.  These exhaust pipes are designed to keep cooling water separated from the exhaust flow to avoid corrosion of valves, rings and pistons.  And these exclusive patented Turbulator Rings have proven themselves in protecting engines against water ingestion due to condensation.

Hardin Exhaust Systems are the overwhelming choice of boaters who want top-end performance with durability.  These exhaust systems deliver by allowing your engine to breathe easier and perform better.  Boaters spend thousands of dollars to modify their engines to increase horsepower and speed.  But, unless the exhaust system is capable of the additional flow required, the modifications are wasted.

These exhaust systems allow center to center engine dimensions of 32-5/16" and are 1-5/8" taller than Mercury cast iron manifolds mounted on stock short decks with GM Heads.

Note:  Pricing indicated includes STANDARD DIMENSION Tailpipes only.  Custom Tailpipes may incur additional charges depending on the length and complexity of the tailpipe required.

Please call for price quotation.

Mercruiser OEM V8 BBC 454/7.4L and 502/8.2L Exhaust Manifold and Riser Kit w/out Spacer

Qty	Description	OEM #
2	Exhaust Elbow	807988Q03
2	Exhaust Manifold Assy. (with  drain plug)	807078T08
2	Gasket-Elbow	27-863724 (2 Slot, Restricted) or 27-863726 (4 Slot, Full Flow), or 27-863725-1  (Block Off, For Closed Cooling)
2	Gasket-Manifold	27-46820

• Direct OEM Manufactured Replacement for Mercruiser Big Block Chevy 454/502 Manifolds and Risers
• Manifolds and 4" Risers Constructed from Cast Iron and painted with black corrosion resistant paint.
• Replaces Mercruiser #807078T08 and 89011A8 Manifolds
• Replaces Mercruiser #807988Q03, 807988A03 and 44354A3 Risers

Mercruiser OEM V8 BBC 454/7.4L and 502/8.2L Exhaust Manifold and Riser Kit w/ 3" Spacer

Qty	Description	OEM #
2	Exhaust Elbow	807988Q03
2	Exhaust Manifold Assy. (with  drain plug)	807078T08
1	3" Spacer Kit with Elbow Gaskets	93320A13
2	Gasket-Manifold	27-46820

• Direct OEM Manufactured Replacement for Mercruiser Big Block Chevy 454/502 Manifolds and Risers
• Manifolds and 4" Risers Constructed from Cast Iron and painted with black corrosion resistant paint.
• Replaces Mercruiser #807078T08 and 89011A8 Manifolds
• Replaces Mercruiser #807988Q03, 807988A03 and 44354A3 Risers

Mercruiser OEM V8 BBC 454/7.4L and 502/8.2L Exhaust Manifold and Riser Kit w/ 6" Spacer

Qty	Description	OEM #
2	Exhaust Elbow	807988Q03
2	Exhaust Manifold Assy. (with  drain plug)	807078T08
1	6" Spacer Kit with Elbow Gaskets	93322A12
2	Gasket-Manifold	27-46820

• Direct OEM Manufactured Replacement for Mercruiser Big Block Chevy 454/502 Manifolds and Risers
• Manifolds and 4" Risers Constructed from Cast Iron and painted with black corrosion resistant paint.
• Replaces Mercruiser #807078T08 and 89011A8 Manifolds
• Replaces Mercruiser #807988Q03, 807988A03 and 44354A3 Risers

Mercruiser GM V8 BBC 454/7.4L and 502/8.2L Raw/Fresh Water Cooling System w/out Spacer

Qty	Description	OEM #
2	Exhaust Elbow	807988A2
2	Exhaust Manifold Assy.	807078A6
2	Gasket-Elbow	27-863724
2	Gasket-Manifold	27-46820
8	Screw-Steel-Zinc Placted	10-43749
2	Hose Fitting w/ Drain Plug Kit	22-806926A1

• Direct Replacement for Mercruiser Big Block Chevy 454/502 Manifolds and Risers
• Manifolds and 4" Risers Constructed from Cast Iron and painted with black corrosion resistant paint.
• Individual Runners for Improved Performance over Stock Manifolds
• Replaces Mercruiser #807078T10 and 89011A8 Manifolds
• Replaces Mercruiser #807988A03 and 44354A3 Risers
• Includes Bolts and Gaskets

Mercury Replacement Big Block Chevy 454/7.4L and 502/8.2L (Cast Iron) 3" Exhaust Kit

Qty	Description	OEM #
2	Exhaust Elbow	98504A3
2	Exhaust Manifold Assy.	807078A6
2	Gasket-Elbow	27-863724
2	Gasket-Manifold	27-46820
8	Flange Serrated Nut	11-49838
8	Stud (Steel)	16-49545
2	Hose Fitting w/ Drain Plug Kit	22-806926A1

• Direct Replacement for Mercruiser Big Block Chevy 454/502 Manifolds and Risers
• Manifolds and 3" Risers Constructed from Cast Iron and painted with black corrosion resistant paint.
• Riser has 15° down angle mounts with studs and nuts 1983-1995 Mercruiser V6, V8 engines with the center rise manifolds, uses 3" hose or bellows
• Individual Runners for Improved Performance over Stock Manifolds
• Replaces Mercruiser #807078T10 and 89011A8 Manifolds
• Replaces Mercruiser #98504A3 Risers
• Includes Bolts and Gaskets

Stock Mercury Replacement BBC 454/7.4L and 502/8.1L Cast Iron Exhaust Kit w/ 3” Spacer
Mercury Big Block Chevy Exhaust kit with 3 Inch Spacer. This kit has 4 Inch Elbow Kit used with 4" exhaust hose. For 1981 & Up.

Qty	Description	OEM #
2	Exhaust Elbow	807988A2
2	Exhaust Manifold Assy.	807078A6
2	Spacer 3"	807476A3
2	Gasket-Fresh Water	27-860231
2	Gasket-Raw Water	27-863724
2	Gasket	27-863726
2	Gasket	27-46820
8	Flange Serrated Nut	11-49836
8	Stud (3/8" x 9-1/2")	16-11375
2	Hose Fitting w/ Drain Plug Kit	22-806926A1

Stock Mercury Replacement BBC 454/7.4L and 502/8.1L Cast Iron Exhaust Kit w/ 6” Spacer
Mercury Big Block Chevy Exhaust Kit with 6 Inch Spacer. This kit has 3 Inch Elbow Kit used with 4" exhaust hose. For 1981 & Up.

Qty	Description	OEM #
2	Exhaust Elbow	807988A2
2	Exhaust Manifold Assy.	807078A6
2	Spacer 6"	807477A2
2	Gasket-Fresh Water	27-860231
2	Gasket-Raw Water	27-863724
2	Gasket	27-863726
2	Gasket	27-46820
8	Screw	10-12244
8	Screw	10-43749
2	Hose Fitting w/ Drain Plug Kit	22-806926A1

Stock Mercury Replacement BBC 454/7.4L and 502/8.1L Cast Iron Exhaust Kit w/ 3” Spacer
Mercury Big Block Chevy Exhaust Kit with 3 Inch Spacer. This kit has 3 Inch Elbow Kit used with 3" exhaust hose. For 1981 & Up.

Qty	Description	OEM #
2	Exhaust Elbow	98504A3
2	Exhaust Manifold Assy.	807078A6
2	Spacer 3"	807476A3
2	Gasket-Elbow	27-863724
2	Gasket-Elbow	27-863726
2	Gasket-Manifold	27-46820
8	Flange Serrated Nut	11-49838
8	Stud	16-97520
2	Hose Fitting w/ Drain Plug Kit	22-806926A1

Stock Mercury Replacement BBC 454/7.4L and 502/8.1L Cast Iron Exhaust Kit w/ 6” Spacer
Mercury Big Block Chevy Exhaust Kit with 6 Inch Spacer. This kit has 3 Inch Elbow Kit used with 3" exhaust hose. For 1981 & Up.

Qty	Description	OEM #
2	Exhaust Elbow	98504A3
2	Exhaust Manifold Assy.	807078A6
2	Spacer 6"	807477A2
2	Gasket-Elbow	27-863724
2	Gasket-Elbow	27-863726
2	Gasket-Manifold	27-46820
16	Screw	10-12244
2	Hose Fitting w/ Drain Plug Kit	22-806926A1

OMC / Volvo Complete Exhaust Kit- BBC V8 454/502 CID (7.4/8.2L)

For 1991 & up applications.
Standard height 4" Hose OMC/Volvo risers 7-3/4" Tall. Used on OMC 89-98 and Volvo 94 and Up

OMC / Volvo Exhaust Kit w/ Hi-Rise Single-Piece Elbow - BBC V8 454/502 CID (1991 & Up)

Tall height, 4" Hose OMC/Volvo risers, 11" Tall. 

Mercruiser Big Block Chevy Exhaust Manifold Kit 454/502 89011A8 / 807078T08

Qty	Description	OEM #
1	Exhaust Manifold	807078T08
1	Hose Fitting w/ Drain Plug	22-806926A1
1	Gasket-Elbow	27-863724
1	Gasket-Manifold	27-46820

• Direct Replacement for Mercruiser Big Block Chevy 454/502 Manifold
• Manifold Constructed from Cast Iron and painted with black corrosion resistant paint.
• Individual Runners for Improved Performance over Stock Manifold
• Replaces Mercruiser #807078T10, 80707T08 and 89011A8, 807078A6 Manifolds.
• Can use with 4" or 3" Riser
• Includes Gaskets
• 3-Year Warranty
• Sold Each.

Exhaust Manifold

For OMC: MODEL 7.4/8.2L - V8 B.B., GM 454/502 CID (1991 & UP)
For Volvo: MODEL 7.4/8.2L - GM 454/502 CID V8 (1992 & UP) #3861459

Standard Big Block Chevy Freshwater Merc Kit 36" Wide - STOCK Measurements

THE ULTIMATE "FRESH WATER" EXHAUST SYSTEM

Finally an affordable alternative to all stainless steel water jacketed headers. For the thousands of pleasure boaters "NOT" affected by the corrosion problems associated with Salt Water there is at last the availability of a true tubular header system for the Fresh Water boater. These headers are designed to be a replacement for Mercury 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. Low Port Headers are also available for under the swim step applications. Standard width headers will have about 1/2" clearance between header and tall style Moroso valve cover. Headers come complete with bolts, gaskets, water fittings, pet cocks, etc. (less 4" hose and 4" hose clamps). Factory oil filter requires relocation.

THE LIGHTNING CONSTRUCTION DIFFERENCE IS WHAT COUNTS !
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 corrosive water environments. Now able to apply the same high tech coating to the fresh water series of steel outer lined thus aiding in the prevention cracking and deterioration.

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

Standard Jacketed Header - Big Block Chevy Jet Drive 36" Wide

These headers are designed to be a replacement for 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, water fittings, 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 330 hp 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 they are 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: All 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.

Hi-Torque Replacement Big Block Manifolds Only (pair)

Set of replacement manifolds only. No pipes. If you find yourself in need of maintenance accessories - we've got them!Gaskets, Clamps, Manifolds, Sealers.  We've got it all!

Big Block GM Hi-Torque Standard Kit

The Hi-Torque manifolds feature state of the art design with a single wall internal casting that is enclosed in a press formed aluminum jacket creating a fully water cooled manifold. A highly polished stainless steel riser comes standard as well as bolts, gaskets and fittings. This system is also covered with an exclusive 5 year warranty. These systems are compatible with silent choice and similar type exhaust diverter systems

Industry wide, Stainless Marine exhaust systems are recognized for increased horsepower, remarkable weight savings, an exclusive five-year warranty and an incredible value.

Tests by both Hot Boat and Trailer Boat Magazines revealed increases of 3.2 to 6.5 MPH on MerCruiser Big Block powered 22'-24' boats.

The unique construction results in the heaviest manifold weighing only 23 pounds A huge savings compared to cast iron Stainless Marine is one of the top quality and least expensive systems available today. Note: All systems based on Bravo applications.

All kits include: Shift, Module, and an Oil Filter Bracket