Custom Marine Inc. – Featured Products
![]() Small Block E-top HeadersCompatible with GM small block LT siamese port engines |
![]() Gen-X HeadersDirect factory replacements for Mercury HP525EFI, HP600SCi and HP700SCi engines |
![]() 496 E-Top HeadersDirect Mercruiser replacement for 496 Mag or 496 HO engine style. Also available for 454/502 engine applications. |
![]() 496 Sport Tube Performance PackageDirect Mercuiser replacement for 496 Mag or 496 HO engine. |
Why CMI?
Every CMI header is built to exacting standards that have made them the number one choice for offshore racers and performance-oriented boaters who demand on-water performance.
CMI headers are manufactured using state-of-the-art materials, like 316L and 317L stainless steel, offering superior corrosion resistance and durability. A unique, patented bending process assures uniform wall thickness and eliminates any rippling and crazing of the tubing during production. Semi-automated tungsten inert gas welding, plus heat treating of the complete manifold following assembly, significantly reduces internal stresses that commonly cause fatigue, corrosion and premature failure in most high performance applications.
To complement its header systems, CMI also manufactures custom tailpipes, exhaust accessories and integral mufflers for virtually any single, dual, triple or quad engine configuration, including small block or big block applications, Chevrolet and Buick V-6s and Ford 460 and SVO's.
With CMI, boaters get a combination of performance and reliability unparalleled by any competitive products on the market.
Best pricing and availability through one of our
CMI Distributors or CMI Authorized Dealers...click here
for details.
It's all about Performance






