Hardin Marine Exhaust - Seaward Series Exhaust Systems

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

• 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

• Manifolds are powder-coated for corrosion protection
• "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

• 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

• 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

• 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

• Manifolds are powder-coated for corrosion protection
• "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

• 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

• Manifold is powder-coated for corrosion protection
• "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

• 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 500+ HP 
• 4" Dry Riser for performance 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

• 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

• Manifolds are powder-coated for corrosion protection
• "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

• Eliminate Catalyzed Exhaust Systems
• 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 up to 400HP 
• 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
• Requires Catalyst Eliminator Computer (See Related Parts)
• 2" Taller Than Stock Risers
• We need to know your current riser height to make sure the risers will fit. See this image, we need height labeled "C". or find the part number on the riser such as in this image.

NOTE: THIS SYSTEM REQUIRES A HIGH DEGREE OF TECHNICAL APTITUDE TO INSTALL AND CONFIGURE. YOU MUST CALL AND SPEAK WITH OUR TECH SUPPORT DEPARTMENT BEFORE GETTING A QUOTE.

WARNING! This system is not to be used on emissions regulated waterways. The intent of this system is to allow the running of a catalyzed marine engine without the catalytic converters installed and without triggering any ECU error codes. With the engine operating in this condition, the emissions control system will be rendered inoperative. For this reason, do not operate the vessel on emissions regulated waterways. This system is not legal for any purpose other than testing purposes and not for use on any state or federal waterway.

• 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 up to 350HP 
• 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
• 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

• 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 up to 350HP 
• 3" Taller 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
• Silent choice, captains call, and select sound exhaust diverter system compatible
• Kit includes all bolts and gaskets needed for installation

• 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 up to 350HP 
• 6" Taller 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
• Silent choice, captains call, and select sound exhaust diverter system compatible
• Kit includes all bolts and gaskets needed for installation

• DO YOU HAVE DRY JOINT EXHAUST? CLICK HERE TO LEARN MORE.
• Mercruiser Dry Joint Replacement
• Replaces 14 degree, Dry Joint "Tall" Riser systems, "Short" 7 degree systems will require custom tailpipes
• The term Mercruiser Dry Joint Exhaust refers to a later model (2002 and newer) OEM exhaust system which utilizes 2 coolant passages vs 4, between the manifold and riser that are separated outside of the exhaust gasket. 
• 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 up to 400HP 
• 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
• Risers include O2 Sensor bungs and plugs.
• MerCruiser changed their exhaust system design in 2002 by creating a Dry-Joint exhaust system thus removing the cooling water passages from the perimeter of the riser and manifold flange area.  Dry-Joint is a proven enhanced design exhaust manifold and exhaust riser compared to standard “Wet-Gasket” style of marine exhaust manifolds and exhaust risers common to early or old style marine industry offerings