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Custom Marine (CMI)

Small Block Chevy E-Top Headers - Satin

Starting From:
$3,683.99
This Part has options, please click the button below to order.

Small Block Chevy E-Top Headers - Polished

650-13157 + Option(s)

Small Block Chevy E-Top Headers - Polished

Works as stock Mercury replacement or for most Stern Drives and Jet boats. 4" Hose connection. Made from 316L Stainless Steel. Bolts directly in the existing location of your stock manifold.

ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 2-3 WEEKS

Small Block Chevy E-Top Headers - Satin

Starting From:
$3,042.99
This Part has options, please click the button below to order.

Small Block Chevy E-Top Headers - Satin

650-13156 + Option(s)

Small Block Chevy E-Top Headers - Satin

Works as stock Mercury replacement or for most Stern Drives and Jet boats. 4" Hose connection. Made from 316L Stainless Steel. Bolts directly in the existing location of your stock manifolds. This is a single engine set and will directly replace both manifolds.

ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 2-3 WEEKS

Sport Tube/Sweeper Clamp Kit
Your Price:
$59.99

Sport Tube/Sweeper Clamp Kit

650-36270

Sport Tube/Sweeper Clamp Kit

This Kit includes:
  • (1) Jumper Hose 1.125" ID, 180 Degree
  • (2) Stainless Steel Hose Clamp #16
  • (1) Sweeper V-Band Clamp
  • (1) Sweeper Tail Gasket

Stainless Steel Distributon Tube Kit for Big Tubes
Your Price:
$838.99

Stainless Steel Distributon Tube Kit for Big Tubes

650-41440

Stainless Steel Distributon Tube Kit for Big Tubes


Standard Rope Seal
Your Price:
$21.99

Standard Rope Seal

650-50340

Standard Rope Seal

Rope Seal for CMI Headers, sold each.

Width is 1/2" and Length is 14 1/2"

115 Deg. Jumper Hose
Your Price:
$12.99

115 Deg. Jumper Hose

650-32040

115 Deg. Jumper Hose


180 Deg. Jumper Hose
Your Price:
$18.99

180 Deg. Jumper Hose - 3/4"

650-32050

180 Deg. Jumper Hose

I.I 3/4"


180 Deg. Jumper Hose Big Tube, 1-3/8" I.D.
Your Price:
$18.99

180 Deg. Jumper Hose Big Tube, 1-3/8" I.D.

650-32200

180 Deg. Jumper Hose Big Tube, 1-3/8" I.D.


180 Deg. Jumper Hose, 1-1/8" I.D.
Your Price:
$13.99

180 Deg. Jumper Hose, 1-1/8" I.D.

650-32100

180 Deg. Jumper Hose, 1-1/8" I.D.


90 Deg. Hose for Distribution Tube
Your Price:
$12.99

90 Deg. Hose for Distribution Tube

650-32030

90 Deg. Hose for Distribution Tube


Adapter to Header 2-3/8" Big Tube Gasket
Your Price:
$30.99

Adapter to Header 2-3/8" Big Tube Gasket

650-34050

Adapter to Header 2-3/8" Big Tube Gasket

Sold Each


Adapter to Header Gasket for 2-1/8", 2-1/4" Big Tube
Your Price:
$30.99

Adapter to Header Gasket for 2-1/8", 2-1/4" Big Tube

650-34060

Adapter to Header Gasket for 2-1/8", 2-1/4" Big Tube

Sold Each


Big Tube Rope Seal, T-Bolt Clamp Kit
Your Price:
$61.99

Big Tube V-Band Clamp

650-36210

Big Tube V-Band Clamp

Big Tube/Big E-Top Clamp, T-Bolt
Your Price:
$86.99

Big Tube/Big E-Top Clamp, T-Bolt

650-36150

Big Tube/Big E-Top Clamp, T-Bolt


Bridge Spacer
Your Price:
$18.99

Bridge Spacer

650-44120

Bridge Spacer


Bridge Spacer Big Tube
Your Price:
$18.99

Bridge Spacer Big Tube

650-44140

Bridge Spacer Big Tube


CMI 454/502 Direct Mercruiser Replacement E-Top Exhaust System, Polished

Starting From:
$4,199.99
This Part has options, please click the button below to order.

CMI 454/502 Direct Mercruiser Replacement E-Top Exhaust System, Polished

650-13185 + Option(s)

CMI 454/502 Direct Mercruiser Replacement E-Top Exhaust System, Polished

The CMI 454/502 E-Top Header Kit is a a true plug and play system. There is no need to purchase additional custom pipes. These are a direct replacement for your stock 454/502 engine. CMI headers offer more water jacketed protection than your stock exhaust can provide. CMI uses the same high quality semi-automated process on these headers as with the entire product line. These headers are fully post annealed to reduce stresses built up in the header during the manufacturing process. Best of all, 454/502 E-Top headers are made to last, they are mandrel bent and formed from hight quality 316L grade material. There are no parts to crack, all CMI collectors are forged from American made Stainless Steel.

Note: All CMI Systems are sold without Talipipes

ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 2-3 WEEKS

CMI 454/502 Direct Mercruiser Replacement E-Top Exhaust System, Polished

Starting From:
$3,599.99
This Part has options, please click the button below to order.

CMI 454/502 Direct Mercruiser Replacement E-Top Exhaust System, Satin

650-13186 + Option(s)

CMI 454/502 Direct Mercruiser Replacement E-Top Exhaust System, Satin

The CMI 454/502 E-Top Header Kit is a a true plug and play system. There is no need to purchase additional custom pipes. These are a direct replacement for your stock 454/502 engine. CMI headers offer more water jacketed protection than your stock exhaust can provide. CMI uses the same high quality semi-automated process on these headers as with the entire product line. These headers are fully post annealed to reduce stresses built up in the header during the manufacturing process. Best of all, 454/502 E-Top headers are made to last, they are mandrel bent and formed from hight quality 316L grade material. There are no parts to crack, all CMI collectors are forged from American made Stainless Steel.

Note: All CMI Systems are sold without Talipipes

ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 2-3 WEEKS

CMI 496 E-Top Tall Polished Exhaust Header System, 2" Taller
Your Price:
$4,899.99

CMI 496 E-Top Polished Exhaust System, 2" Taller

650-13177

CMI 496 E-Top Tall Polished Exhaust Header System, 2" Taller

How to measure riser height

Direct Mercruiser replacement for your 496 Mag or 496 HO engine. 10-1/2" Stock Tall Riser Height. Polished. No additional custom tails to buy. You don’t need to remove your stock exhaust hose to install our kit, a true plug and play system.

Direct Mercruiser replacement for your 496 Mag or 496 HO engine.

No additional custom tails to buy. You don’t need to remove your stock exhaust hose to install this kit, a true plug and play system.

  • 1 7/8" id primary to get peak horse power and torque.
  • Mandrel bent and formed from High quality 316L grade material.
  • Fully post annealed to reduce stresses built up in the header during the manufacturing process
  • Seamless water jacketed header. No welded inner primaries or water jacketed tubes to crack and leak.
  • More water jacketed protection than your stock exhaust.
  • Approved by Mercruiser to not void warranty on the motor, with the exception of water reversion.
  • Same high quality semi automated welding as used on all racing applications
  • Cool collar patented flange design to eliminate the risk of getting water in the motor by the head flange
  • This kit is price competitive to other aluminum/stainless manifold systems with superior performance and extended life span in harsh marine environments.
  • No cast parts to crack, all CMI collectors are forged from American made stainless steel.
  • Works on 34.5" drive centers
  • Brings a race look to your stock engine.
  • Sophisticated engineering leaves your stock oil lines in place and only requires relocating your oil filter with a supplied bracket.
  • Step by step, do it yourself instructions using Mercury supplied engine schematics.
  • Exhaust Water Temperature Bungs Installed as Standard Equipment.
ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 2-3 WEEKS

CMI 496 E-Top Satin Exhaust Header Systems
Your Price:
$3,699.99

CMI 496 E-Top Satin Exhaust Header Systems

650-13176

CMI 496 E-Top Satin Exhaust Header Systems

How to measure riser height

Direct Mercruiser replacement for your 496 Mag or 496 HO engine. 8-1/2" Stock Riser Height. Polished. No additional custom tails to buy. You don’t need to remove your stock exhaust hose to install this kit, a true plug and play system.

Direct Mercruiser replacement for your 496 Mag or 496 HO engine.

No additional custom tails to buy. You don’t need to remove your stock exhaust hose to install this kit, a true plug and play system.

  • 1 7/8" id primary to get peak horse power and torque.
  • Mandrel bent and formed from High quality 316L grade material.
  • Fully post annealed to reduce stresses built up in the header during the manufacturing process
  • Seamless water jacketed header. No welded inner primaries or water jacketed tubes to crack and leak.
  • More water jacketed protection than your stock exhaust.
  • Approved by Mercruiser to not void warranty on the motor, with the exception of water reversion.
  • Same high quality semi automated welding as used on all racing applications
  • Cool collar patented flange design to eliminate the risk of getting water in the motor by the head flange
  • This kit is price competitive to other aluminum/stainless manifold systems with superior performance and extended life span in harsh marine environments.
  • No cast parts to crack, all CMI collectors are forged from American made stainless steel.
  • Works on 34.5" drive centers
  • Brings a race look to your stock engine.
  • Sophisticated engineering leaves your stock oil lines in place and only requires relocating your oil filter with a supplied bracket.
  • Step by step, do it yourself instructions using Mercury supplied engine schematics.
  • Exhaust Water Temperature Bungs Installed as Standard Equipment.
ALL CMI HEADERS ARE MADE TO ORDER AND SHIP FROM THE FACTORY IN 2-3 WEEKS