Quicksilver 866178A02 Exhaust Manifold Conversion Kit 496 Magnum 8.1S MerCruiser

The Quicksilver 866178A02 Exhaust Manifold Conversion Kit is a genuine Mercury Marine OEM replacement designed to upgrade older-style exhaust manifolds on MerCruiser sterndrive and inboard engines. This kit converts the original aluminum exhaust manifolds with separate external water rails to the newer, more durable cast iron manifold design without water rails, bringing aging cooling systems up to current Mercury Marine standards.

The cast iron manifold features an internal ceramic coating on all coolant passages and a protective coating on the exterior finish, providing enhanced resistance to corrosion — a critical performance factor in the harsh marine environment. The manifolds may be replaced individually, and using a cast iron manifold alongside the existing aluminum manifold on the same engine is acceptable.

What's Included:

• Cast iron exhaust manifold (replaces either port or starboard)
• Gasket
• Drain plug
• O-ring
• Drain elbow
• All hardware required for conversion (note: some included parts will not be used depending on which manifold is being replaced)

Key Features:

• Converts older water-rail manifold design to updated integrated cast iron construction
• Internal ceramic coating protects coolant passages from corrosion
• Exterior coating provides lasting protection against the marine environment
• Produced to Mercury Marine OEM specifications for precise fit and performance
• Genuine Quicksilver / Mercury Marine factory part — not aftermarket
• Manifolds can be replaced individually or as a pair

Engineered and tested to meet Mercury Marine original equipment manufacturer specifications, the 866178A02 ensures your 496 Magnum or 8.1S MerCruiser engine continues to perform reliably. Quicksilver parts are the premier choice for MerCruiser sterndrive and inboard engine maintenance and restoration.