IMCO Marine

PowerFlow Plus Manifold and 90° Riser Kit Polished

To view and download the PDF line drawing  CLICK HERE

To view and download the PDF water hose diagram  CLICK HERE

PowerFlow Plus Manifold and 90° Riser Kit Polished

IMCO's innovative patented cast aluminum manifolds and risers are designed with internal runners for 510 cubic inch, naturally aspirated, or blown big block Chevy engines. Fully water-jacketed with 2 1/4" primaries, they are equal to any tubular header on the market today. Dyno results have proven that PowerFlow Plus out performs headers in torque, rpm, horsepower, and most of all longevity. All stainless steel tail pies are custom made to your exact specifications. We off several internal mufflers for you to choose.

To view and download the PDF line drawing  CLICK HERE

To view and download the PDF water hose diagram  CLICK HERE

PowerFlow Plus Manifold and 85° Riser Kit Polished

IMCO's innovative patented cast aluminum manifolds and risers are designed with internal runners for 510 cubic inch, naturally aspirated, or blown big block Chevy engines. Fully water-jacketed with 2 1/4" primaries, they are equal to any tubular header on the market today. Dyno results have proven that PowerFlow Plus out performs headers in torque, rpm, horsepower, and most of all longevity. All stainless steel tail pies are custom made to your exact specifications. We off several internal mufflers for you to choose.

PowerFlow Manifold Bolt Kit (For 1 manifold only)

Kit Includes

4 3/8-16 x 4 1/2" Bolt.....................08-010806222
4 3/8-16 x 1 1/2" Bolt.....................08-010806102
4 3/8" x 2" Stud............................08-130803121
8 3/8" AN S/S Washer...................08-100800001
4 3/8-24 12 Point Nut.....................08-180803001
1 Riser Gasket.............................11-1005

Black PowerFlow Plus (Comes with all necessary hardware & gaskets). (Sold in pairs)

IMCO's innovative patented cast aluminum manifolds and risers are designed with 33" internal runners for those 510 and bigger cubic inch, naturally aspirated, or blown big block Chevy motors. Fully water-jacketed with NO water passing though the flange area of the manifold or riser pipe. Manifold has 2 1⁄4" primary runners they are equal to any tubular header on the market today. Dyno results have proven that PowerFlow Plus out performs most headers in torque, rpm, horsepower, and most of all longevity. Risers are available in three different configurations, three different heights, and two finishes Polished or Black. Black manifolds are hard coat anodized inside and out to withstand tough marine environments. All stainless steel tail pipes are custom made to your exact specifications. We also offer several different internal mufflers systems for you to choose. Please call IMCO for further information.

Polished PowerFlow Plus (Comes with all necessary hardware & gaskets). (Sold in pairs)

IMCO's innovative patented cast aluminum manifolds and risers are designed with 33" internal runners for those 510 and bigger cubic inch, naturally aspirated, or blown big block Chevy motors. Fully water-jacketed with NO water passing though the flange area of the manifold or riser pipe. Manifold has 2 1⁄4" primary runners they are equal to any tubular header on the market today. Dyno results have proven that PowerFlow Plus out performs most headers in torque, rpm, horsepower, and most of all longevity. Risers are available in three different configurations, three different heights, and two finishes Polished or Black. Black manifolds are hard coat anodized inside and out to withstand tough marine environments. All stainless steel tail pipes are custom made to your exact specifications. We also offer several different internal mufflers systems for you to choose. Please call IMCO for further information.

PowerFlow Plus riser Gasket, Manifold to riser gasket. (Sold EACH)

PowerFlow Plus Riser Bolt Kit (Includes enough parts for a pair of risers)

Kit Includes

8 3/8-16 x 2" Stud...................08-130806121
8 3/8-16 Nut............................08-200806001
8 3/8 AN S/S Washer..............08-100800001
2 Tail Pipe Gasket...................11-1006

Powerflow Plus System - Black manifolds and risers - 30 degree

IMCO's totally new Powerflow Plus cast aluminum, fully water-jacketed exhaust manifolds are available in black or polished. Black manifolds and risers are hard-coat anodized inside and out to withstand the tough marine environment. The new Powerflow Plus featuresIMCO's innovative patented design with 33" internal runners and a new ultra hi-flow exhaust riser. Brackets are available for this system.

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

The outside manifold surfaces are then coated with the highest quality epoxy powder coating available, creating a part that not only is highly corrosion resistant, but good looking as well. Features an external fitting to accept stock MerCruiser thermostat plumbing.

Powerflow Plus System - Black manifolds and risers - 85 degree

IMCO's totally new Powerflow Plus cast aluminum, fully water-jacketed exhaust manifolds are available in black or polished. Blackmanifolds and risers are hard-coat anodized inside and out to withstand the tough marine environment. The new Powerflow Plus features IMCO's innovative patented design with 33" internal runners and a new ultra hi-flow exhaust riser. Brackets are available for this system.

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

The outside manifold surfaces are then coated with the highest quality epoxy powder coating available, creating a part that not only is highly corrosion resistant, but good looking as well. Features an external fitting to accept stock MerCruiser thermostat plumbing.

Powerflow Plus System - Polished manifolds and risers - 30 degree

IMCO's totally new Powerflow Plus cast aluminum, fully water-jacketed exhaust manifolds are available in black or polished. Black manifolds and risers are hard-coat anodized inside and out to withstand the tough marine environment. The new Powerflow Plus features IMCO's innovative patented design with 33" internal runners and a new ultra hi-flow exhaust riser. Brackets are available for this system.

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

 The outside manifold surfaces are then coated with the highest quality epoxy powder coating available, creating a part that not only is highly corrosion resistant, but good looking as well. Features an external fitting to accept stock MerCruiser thermostat plumbing.

Powerflow Plus System - Polished manifolds and risers - 85 degree

IMCO's totally new Powerflow Plus cast aluminum, fully water-jacketed exhaust manifolds are available in black or polished. Black manifolds and risers are hard-coat anodized inside and out to withstand the tough marine environment. The new Powerflow Plus features IMCO's innovative patented design with 33" internal runners and a new ultra hi-flow exhaust riser. Brackets are available for this system.

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

 The outside manifold surfaces are then coated with the highest quality epoxy powder coating available, creating a part that not only is highly corrosion resistant, but good looking as well. Features an external fitting to accept stock MerCruiser thermostat plumbing.

Powerflow Polished Small Block Manifolds Only Kit 

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

The outside manifold surfaces are polished. Features an external fitting to accept stock MerCruiser thermostat plumbing. Kit includes gaskets and bolts.

Powerflow Polished Small Block System with Stainless Silent Choice Risers

This popular system allows the use of a switchable exhaust diverter. These risers are stainless steel and custom designed to ease installation. They use a standard 4" diverter connection.

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

The outside manifold surfaces are polished. Features an external fitting to accept stock MerCruiser thermostat plumbing.

Black Small Block Manifolds. (Sold in pairs)

These manifolds were designed for high horsepower 350 cid to 427 cid engines that are making 350 HP Plus. Manifolds have a 1 1⁄2" I.D. runner with a tall D port entry. The outlet is 3" with a stainless steel air straightened plate to direct exhaust into riser pipe for maximum scavenging.

Manifolds will work with angled spark plugged heads or straight spark plugged heads. Also you can use tall valve covers for various rocker arm assemblies and stud girdle. Manifolds are available in black powder coated, hard anodized or polished in standard or recirc manifolds.

The risers are highly polished stainless steel, and are designed for 4" exhaust tips. We offer a wide variety of riser pipe configurations (AS SHOWN IN RISER PIPE SECTION), to accommodate just about every application. Custom riser pipes can also be manufactured to order, just give us a call for details.

Polished small block manifolds. (Sold in pairs)

These manifolds were designed for high horsepower 350 cid to 427 cid engines that are making 350 HP Plus. Manifolds have a 1 1⁄2" I.D. Runner with a tall D port entry. The outlet is 3" with a stainless steel air straightened plate to direct exhaust into riser pipe for maximum scavenging.

Manifolds will work with angled spark plugged heads or straight spark plugged heads. Also you can use tall valve covers for various rocker arm assemblies and stud girdle. Manifolds are available in black powder coated, hard anodized or polished in standard or recirc manifolds.,/p> The risers are highly polished stainless steel, and are designed for 4" exhaust tips. We offer a wide variety of riser pipe configurations (AS SHOWN IN RISER PIPE SECTION), to accommodate just about every application. Custom riser pipes can also be manufactured to order, just give us a call for details.

Black small block recirculation manifolds. (Sold in pairs)

These manifolds were designed for the water to recirculate or preheat (no water passes through riser pipe flange) high horsepower 350 cid to 427 cid engines that are making 350 HP Plus. Manifolds have a 1 1⁄2" I.D. Runner with a tall D port entry. The outlet is 3" with a stainless steel air straightened plate to direct exhaust into riser pipe for maximum scavenging.

Manifolds will work with angled spark plugged heads or straight spark plugged heads. Also you can use tall valve covers for various rocker arm assemblies and stud girdle. Manifolds are available in black powder coated, hard anodized.

The risers are highly polished stainless steel, and are designed for 4" exhaust tips. We offer a wide variety of riser pipe configurations (AS SHOWN IN RISER PIPE SECTION), to accommodate just about every application. Custom riser pipes can also be manufactured to order, just give us a call for details.

Polished small block recirculation manifolds. (Sold in pairs)

These manifolds were designed for the water to recirculate or preheat (no water passes through riser pipe flange) high horsepower 350 cid to 427 cid engines that are making 350 HP Plus. Manifolds have a 1 1⁄2" I.D. Runner with a tall D port entry. The outlet is 3" with a stainless steel air straightened plate to direct exhaust into riser pipe for maximum scavenging.

Manifolds will work with angled spark plugged heads or straight spark plugged heads. Also you can use tall valve covers for various rocker arm assemblies and stud girdle. Manifolds are available in black powder coated, hard anodized.

The risers are highly polished stainless steel, and are designed for 4" exhaust tips. We offer a wide variety of riser pipe configurations (AS SHOWN IN RISER PIPE SECTION), to accommodate just about every application. Custom riser pipes can also be manufactured to order, just give us a call for details.

Powerflow Small Block Bolt Kit. Kit is for one manifold only.

Powerflow Small Block Kit with Stainless Risers

Powerflow now offers a small block system. This system is designed after the big block kit using the same riser system. This system will increase your torque and horsepower by 10%. This system is also available fully polished, too.

Powerflow manifolds are manufactured using the finest materials and most advanced techniques available. The high quality aluminum manifold castings feature water jackets that surround each exhaust passage, including the port, to eliminate the possibility of burn out.

 The outside manifold surfaces are then coated with the highest quality epoxy powder coating available, creating a part that not only is highly corrosion resistant, but good looking as well. Features an external fitting to accept stock MerCruiser thermostat plumbing.

To view and download the PDF line drawing Left Side  CLICK HERE

To view and download the PDF line drawing Right Side  CLICK HERE

To view and download the PDF water hose diagram  CLICK HERE

PowerFlow Small Block Manifold and "A" Riser Kit (Sold in pairs)

Shown with optional riser bung. These manifolds were designed for high horsepower 350 cid to 427 cid engines that are making 350 HP Plus. Manifolds have a 1 1/2" I.D. runner with a tall D port entry. The outlet is 3" with a stainless steel air straightened plate to direct exhaust into riser pipe for maximum scavenging. Manifolds will work with angled spark plugged heads or straight spark plugged heads. Also you can use tall valve covers for various rocker arm assemblies and stud girdle. Black manifolds are hard anodized prior to powder coat, to ensure against corrosion.

Weight savings of 65 lbs over cast iron and allows for twin installation down to 30" centers.

Small Block std. Stainless steel "A" risers are designed for stock Mercruiser Bravo exhaust tip locations. 3/4"npt fitting is used on front of pipe for thermostat housing that have (4) 1" hoses water to go to exhaust manifolds if needed click on (ADD BUNG). Shift bracket, ECM, or EFI brackets available as bolt on or welded to the risers. To order see PowerFlow accessories or click on "Related Products" on the right side of screen.