HOLIDAY SCHEDULE!

WE WILL BE CLOSED THURSDAY AND FRIDAY NOVEMBER 27th & 28th TO CELEBRATE THANKSGIVING AND WILL REOPEN ON MONDAY, DECEMBER 1st.

All orders placed during this time will be processed on Monday, December 1st when we resume our normal business hours.

HAPPY THANKSGIVING FROM THE TEAM AT MY INBOARD MARINE & GOD BLESS YOU!

Mercruiser GM Big Block Center Rise Exhaust Manifold | Sierra 18-1957-2

$334.00 $425.68


Center rise exhaust manifold fits Mercruiser GM 7.4L & 8.2L CID marine engines.

  • Mercruiser exhaust manifold
  • Direct replacement manifold fits Mercruiser GM V8 454 and 502 cu. in. engines with center riser
  • For Mercruiser 330, 340, & 454 Magnum model engines
  • Interchangeable between port and starboard side
  • Heavy duty cast iron
  • Painted black
  • Includes all gaskets, short riser studs, drain elbow, and plugs
  • Manifold mounting kit P/N 18-8532 – sold separately
  • Replaces Mercruiser 89011A8, 807078A2, 807078A4, 807078A6, 807078T09, 807078T10
  • Replaces Mallory 9-40506
  • Replaces Osco 9011A
  • Replaces Sierra 18-1957, 18-1957-1