Hardin Marine Exhaust - LS Chevy Manifolds

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

part options
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

MULTIPLE PART NUMBER OPTIONS. CLICK PART OPTIONS FOR MORE INFO ->

  • 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 HP" LT Chevrolet Exhaust System

part options
Starting From:
$3,899.99

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

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

MULTIPLE PART NUMBER OPTIONS. CLICK PART OPTIONS FOR MORE INFO ->

  • 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

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

part options
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

MULTIPLE PART NUMBER OPTIONS. CLICK PART OPTIONS FOR MORE INFO ->

  • 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 Low Exit" LT Chevrolet Exhaust System

part options
Starting From:
$3,799.99

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

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

MULTIPLE PART NUMBER OPTIONS. CLICK PART OPTIONS FOR MORE INFO ->

  • 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

part options
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

MULTIPLE PART NUMBER OPTIONS. CLICK PART OPTIONS FOR MORE INFO ->

  • 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 XL" LT Chevrolet Exhaust System

part options
Starting From:
$2,699.99

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

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

MULTIPLE PART NUMBER OPTIONS. CLICK PART OPTIONS FOR MORE INFO ->

  • 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

Seaward Series "Alpha/Bravo" LS Chevrolet Exhaust System

part options
Starting From:
$2,199.99

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

Seaward Series "Alpha/Bravo" LS Chevrolet Exhaust System

MULTIPLE PART NUMBER OPTIONS. CLICK PART OPTIONS FOR MORE INFO ->

  • 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 "Alpha/Bravo" LT Chevrolet Exhaust System

part options
Starting From:
$2,499.99

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

Seaward Series "Alpha/Bravo" LT Chevrolet Exhaust System

MULTIPLE PART NUMBER OPTIONS. CLICK PART OPTIONS FOR MORE INFO ->

  • 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

Seaward Series "Jet Boat / Inboard" LS Chevrolet Exhaust System

part options
Starting From:
$2,399.99

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

Seaward Series "Jet Boat / Inboard" LS Chevrolet Exhaust System

MULTIPLE PART NUMBER OPTIONS. CLICK PART OPTIONS FOR MORE INFO ->

  • 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

Seaward Series "Jet Boat" LT Chevrolet Exhaust System

part options
Starting From:
$2,699.99

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

Seaward Series "Jet Boat" LT Chevrolet Exhaust System

MULTIPLE PART NUMBER OPTIONS. CLICK PART OPTIONS FOR MORE INFO ->

  • 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

LS1 Small Block Chevy Exhaust System
Your Price:
$2,699.99

LS-M Marine Aluminum Exhaust Manifold System for GM 4.8, 5.3, 6.0, 6.2

620-32950

LS-M Marine Aluminum Exhaust Manifold system for GM LS BASED 4.8, 5.3, 6.0, 6.2

These Next generation NEW LS-M series Aluminum exhaust manifold system is a perfect complement to OEM GM LS based engine platforms up to the GM LSA of 550HP. The New LS-M Series Manifolds feature DUAL O2 sensor bung provisions mounted sleekly with one in each exhaust riser. The LS-M series exhaust system also features the ability to be plumbed for either fresh water or closed cooling options. 4" exhaust hose connection is standard. Yet another new feature of the LS-M manifolds is their corrosive hard anodizing feature to yet extend longevity in harsh environments. These manifolds were developed on OEM performance engines and are NOT for use with engines using a camshaft with more than .226 @ .050 Camshaft Duration.

ATTENTION** This Exhaust System is sold in a Painted Industrial finish. Installers will be required to apply further extensive aesthetic final detail finishing. The outside is ROUGH machine and sanded aluminum with Industrial grade painting. Additional Sanding, Polishing, Powder coating or Painting is the responsibility of the purchaser!


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.