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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