Seaward Series Exhaust Systems - Seaward Series Accessories and Tailpipes

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.

Custom 8.2L Seaward Risers 11-3/8" Tall
Your Price:
$1,499.99

Custom 8.2L Seaward Risers 11-3/8" Tall

620-38098

Seaward Custom 8.2L Risers - Sold As A Pair, 11-3/8" tall

Limited stock available, custom height risers. If you are in the market for a Seaward 8.2L system talk to a salesman to see if these fit your application, as it may have considerable cost reductions over building new risers.


Extreme Duty Hi-Performance D Port Exhaust Manifold Gaskets - 454/502/8.2L Chevy
Your Price:
$59.99

Extreme Duty Hi-Performance D Port Exhaust Manifold Gaskets - 454/502/8.2L Chevy

300-1417

Extreme Duty Hi-Performance D Port Exhaust Manifold Gaskets - 454/502/8.2L Chevy - Sold in Pairs - Replaces OEM Mercury #27-8M0065690

These gaskets are graphite impregnated and designed to withstand the highest of temperatures on high horsepower applications. For those of you looking to do the job only once, insist on Hardin Marine Extreme Duty gaskets. Quite possibly the last gasket you'll ever need. These gaskets are designed to be used in D port Exhaust applications. Replaces stock OEM Mercury #27-8M0065690

Sold in Pairs


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.

Replacement Seaward Series 8.1L / 496 Riser Install Kit
Your Price:
$59.99

Replacement Seaward Series 8.1L / 496 Riser Install Kit

620-38071

This kit contains the fittings and bolts to install a pair of risers on a 8.1L / 496 Mercrusier Seaward exhaust system.


Replacement Seaward Series Big Block Chevy Manifold Install Kit
Your Price:
$69.99

Replacement Seaward Series Big Block Chevy Manifold Install Kit

620-38032

This kit contains the fittings and bolts to install a pair of manifolds on a big block Chevy Seaward exhaust system.


Replacement Seaward Series Big Block Chevy Riser Install Kit
Your Price:
$69.99

Replacement Seaward Series Big Block Chevy Riser Install Kit

620-38036

This kit contains the gaskets, hoses and bolts to install a pair of risers on a big block Chevy Seaward exhaust system.


Replacement Seaward Series Small Block Chevy Manifold Install Kit
Your Price:
$59.99

Replacement Seaward Series Small Block Chevy Manifold Install Kit

620-38031

This kit contains the fittings and bolts to install a pair of manifolds on a small block Chevy Seaward exhaust system.


Replacement Seaward Series Small Block Chevy Riser Install Kit
Your Price:
$64.99

Replacement Seaward Series Small Block Chevy Riser Install Kit

620-38046

This kit contains the gaskets, hoses and bolts to install a pair of risers on a small block Chevy Seaward exhaust system.


Stainless Steel 18MM Oxygen Sensor Plug - Hex Head
Your Price:
$23.95

Stainless Steel 18MM Oxygen Sensor Plug - Hex Head

620-50033

Stainless Steel 18MM Oxygen Sensor Plug - Hex Head

This plug only is designed fit popular O2 bungs and ports designed to allow you to cap/plug a oxygen sensor bung  Price does not include bung only plug. Sold Each. 18mm x 1.5, Hex Head.

Note: This is a plug only

Water Inlet Tee Fitting for SBC Dry Joint Seaward Systems
Your Price:
$89.99

Water Inlet Tee Fitting for SBC Dry Joint Seaward Systems

620-38130

Tee fitting.  3/4" NPT port. 1" Hose barbs. Typically used in SBC Dry Joint Seaward Exhaust applications.

Extreme Duty Hi-Performance Exhaust Manifold Gaskets - 454/502 Chevy
Your Price:
$29.99

Extreme Duty Hi-Performance Seaward / Cyclone Exhaust Manifold Gaskets - 454/502/525 Chevy

300-1413

Extreme Duty Hi-Performance Seaward / Cyclone Exhaust Manifold Gaskets - Stock Square Port 454/502/525 Chevy - Sold in Pairs

These gaskets are graphite impregnated and designed to withstand the highest of temperatures on high horsepower applications. Double drilled for both standard BBC and 525 applications. These gaskets are designed to be used with Hardin Marine's Seaward / Cyclone Exhaust Manifolds. Will work on other Big Block Chevy Manifolds as well. 

Sold in Pairs


Seaward Series Replacement Riser Gasket
Your Price:
$11.99

Seaward Series Replacement Riser Gasket

620-38006

Replacement riser gasket for Hardin Seaward manifolds and risers. 4-1/2" x 3" Bolt pattern.


Seaward Turbulator
Your Price:
$37.99

Seaward Turbulator

620-38089

Seaward Turbulator

Designed for seaward series exhaust systems.

Turbulators are designed to keep any condensation or moisture from entering the manifold during the cool down process This is one of the many unique Hardin features that are helping lead the way in exhaust system technologies. Sold each, gaskets sold separately. 2 gaskets are needed per 1 turbulator.

Seaward Series Shift Quadrant / EFI Bracket
Your Price:
$59.99

Seaward Series Shift Quadrant / EFI Bracket

620-38051

This Shift / EFI bracket fits Hardin Marine Seaward Series Exhaust Systems. Can be used for either application.

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


Seaward Series Oil Filter Bracket
Your Price:
$109.99

Seaward Series Oil Filter Bracket

620-38050

This oil filter bracket fits Hardin Marine Seaward Series Exhaust Systems.

Seaward O2 Oxygen Sensor Adapter Flange
Your Price:
$99.99

Seaward O2 Oxygen Sensor Adapter Flange

620-38080

Whether you're a tuner seeking to add a popular Air/Fuel ratio gauge or you're entering the world of aftermarket fuel injection we have developed the critical part to make this addition a snap. This billet aluminum anodized wedge is at just the perfect angle to allow re-connection of your original exhaust hose. The kit includes (1) O2 adapter wedge, (2) gaskets, and (2) new front attachment studs. Bolt pattern is 3" x 4.5". Designed to fit the Hardin Marine Seaward Manifolds only.


Seaward O2 Wedge / Gauge Kit

Your Price:
$409.99

Seaward O2 Wedge / Gauge Kit

620-38081 + Option(s)

Seaward O2 Wedge / Gauge Kit

  • Gauge kit includes custom tuned .1 AFR Resolution Bosch LSU 4.9 Sensor, 8ft. wiring harness, 304 stainless steel weld-in bung, mounting hardware, and detailed instructions for installation
  • 0-5v data and serial data outputs for ECU, data acquisition unit, or Laptop tuning
  • User programmable range for Rich/Stoic/Lean conditions
  • Peak recall/memory
  • 10:1 to 20:1 AFR range for gasoline applications
  • 12 and 16 volt compatible, compatible with nearly every street car or race car electrical system
  • User Programmable Warning Function
  • Display data in Lambda or numerical A/F ratio

Whether you're a tuner seeking to add a popular Air/Fuel ratio gauge or you're entering the world of aftermarket fuel injection we have developed the critical part to make this addition a snap. This billet aluminum anodized wedge is at just the perfect angle to allow re-connection of your original exhaust hose. The kit includes (1) O2 adapter wedge, (1) gasket, and (2) new front attachment studs.


Stainless Steel 18MM Oxygen Sensor Plug
Your Price:
$23.95

Stainless Steel 18MM Oxygen Sensor Plug

620-50031

Stainless Steel 18MM Oxygen Sensor Plug

This plug only is designed fit popular O2 bungs and ports designed to allow you to cap/plug a oxygen sensor bung  Price does not include bung only plug. Sold Each. 18mm x 1.5

Note: This is a plug only

Seaward Aluminum Exhaust Manifold Anti-Corrosion Kit
Your Price:
$42.95

Seaward Aluminum Exhaust Manifold Anti-Corrosion Kit

620-38125

This add-on anti-corrosion kit fits Hardin Marine Seaward Series Exhaust Systems or any other aluminum manifold with a 3/4" NPT port.