Polished 520 GenX Header
CMI GenX headers are direct factory replacement for Mercury HP 525 EFI, 565 EFI, HP 600 SCi and HP 700 SCi engines. When used on a Mercury 520 you get all the features of our standard GenX header, downturn collector provides improved water fill, 316L stainless steel, patented “Cool Collar” design provides a short hot section at the flange, which helps minimize the possibility of water ingestion into the engine. On the GenX header you also get the dual bolt pattern for both the Mercury platform and the standard GM pattern. The 520 header increases in Horsepower up to 48 HP and will improve mid-range acceleration and torque. All GenX headers come in a polished finish with tailpipes sold separately that can be custom made to fit your application.
Mercury / Big Block / Sport Tube / Gen-X