Hardin Marine Exhaust - Seaward Series Exhaust Systems

With the overwhelming success of the performance of Seaward exhaust manifold system it was only natural to expand into even more offerings. This latest version uses the popular Seaward Ocean Series manifolds combined with a intersecting companion pipe allow for direct replacement of rotting, cracked, failing original elbow top styled headers while providing the unmatched durability of a performance manifold system. This system allow's the original tailpipes to be reused for simplicity and affordability of exhaust replacement.

• Manifold is powder-coated for corrosion protection
• Optional "Ocean Series" Extreme Corrosion Treatment available for additional interior corrosion protection 
• HP Riser for high performance performance applications.
• CMI Flange on riser uses existing tailpipes.
• Also replaces Mercury HP 500 EFI applications. 
• 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 bolts and gaskets needed for installation

Riser Jump Hose

Replacement Riser Jump Hose for Seaward Risers

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.

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.

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

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

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.

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

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.