Hardin Marine Exhaust - LS Chevy Manifolds

Seaward Series "Alpha/Bravo HP" LS Chevrolet Exhaust System

Starting From:
$3,599.95

This Part has options, please click the button below to order.

Seaward Series "Alpha/Bravo HP" LS Chevrolet Exhaust System

620-38153 + Option(s)

  • 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

Seaward Series "Alpha/Bravo Low Exit" LS Chevrolet Exhaust System

Starting From:
$3,499.99

This Part has options, please click the button below to order.

Seaward Series "Alpha/Bravo Low Exit" LS Chevrolet Exhaust System

620-38155 + Option(s)

  • 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

Seaward Series "Alpha/Bravo XL" LS Chevrolet Exhaust System

Starting From:
$2,399.99

This Part has options, please click the button below to order.

Seaward Series "Alpha/Bravo XL" LS Chevrolet Exhaust System

620-38156 + Option(s)

  • 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

Seaward Series "Alpha/Bravo" LS Chevrolet Exhaust System

Starting From:
$2,199.99

This Part has options, please click the button below to order.

Seaward Series "Alpha/Bravo" LS Chevrolet Exhaust System

620-38152 + Option(s)

  • 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

Seaward Series "Jet Boat" LS Chevrolet Exhaust System

Starting From:
$2,399.99

This Part has options, please click the button below to order.

Seaward Series "Jet Boat" LS Chevrolet Exhaust System

620-38154 + Option(s)

  • 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

LS1 Small Block Chevy Exhaust System
Your Price:
$10.99

Riser Gasket for LS Marine Aluminum Exhaust Manifold System

620-32494

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.


LS1 Small Block Chevy Exhaust System
Your Price:
$59.99

ECM Bracket for LT Marine Aluminum Exhaust Manifold System

620-32490

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.


LS1 Small Block Chevy Exhaust System
Your Price:
$59.99

Shift Bracket for LS Marine Aluminum Exhaust Manifold System

620-32492

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.


LS1 Small Block Chevy Exhaust System
Your Price:
$32.99

Exhaust Gaskets for LS Marine Aluminum Exhaust Manifold System

620-32496

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.


LS1 Small Block Chevy Exhaust System
Your Price:
$200.00

Extra O2 Bung for LS Marine Aluminum Exhaust Manifold System

620-32941

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.