Sierra 18-1966-1 Manifold, Replaces 806867A2, Fits Mercruiser 3.0L/LX 1990 & Newer

The Sierra 18-1966-1 is a manifold engineered as a direct OE replacement for Mercruiser 3.0L/LX inboard/outboard engines built 1990 and newer, as well as the Marine Power Engine Model E181S. It is designed to be fully interchangeable with the original equipment manifolds it replaces, so it bolts in using the same mounting points and connections as the factory part it is standing in for. The manifold arrives primed and painted, giving it a layer of corrosion protection for the marine engine compartment environment, and it is ready to install straight out of the box without additional prep work. This makes it a straightforward swap for boat owners and marine technicians replacing a cracked, corroded, or failed manifold on a 3.0L/LX Mercruiser I/O powerplant. At 49 pounds, it matches the weight profile of the OEM manifold it is built to replace, and it is finished in black to match typical engine hardware. Because it carries the same Sierra part number system used across the marine aftermarket, it cross-references directly to the OEM numbers used to identify the original Mercruiser manifold, helping buyers confirm compatibility before ordering.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-1966-1
• Product Type: Manifold
• Fitment: Mercruiser 3.0L/LX (1990 & Newer); Marine Power Engine Model E181S
• Weight: 49 pounds
• Color: Black
• Country of Origin: Taiwan
• Quantity: 1 manifold per package
• UPC: 808282371456

Fitment

• Mercruiser 3.0L/LX (1990 & Newer)
• Marine Power Engine Model E181S

Replaces (OEM)

• 806867A2
• 806867A3
• 806867A8
• 806867A9
• 806867A12
• 816329A3
• 860235A03
• 99798A18

Frequently Asked Questions

What engines does the Sierra 18-1966-1 manifold fit? The 18-1966-1 fits Mercruiser 3.0L/LX engines built 1990 and newer, as well as the Marine Power Engine Model E181S.

Is the 18-1966-1 a direct OEM replacement? Yes, this manifold is manufactured as a direct OE replacement and is fully interchangeable with the original equipment manifolds it replaces.

What OEM part numbers does the 18-1966-1 cross-reference to? The 18-1966-1 manifold cross-references OEM numbers 806867A2, 806867A3, 806867A8, 806867A9, 806867A12, 816329A3, 860235A03, and 99798A18.

How much does this manifold weigh? The Sierra 18-1966-1 manifold weighs 49 pounds.

Does the manifold need to be painted before installation? No, the 18-1966-1 arrives primed and painted, so it is ready to install out of the box.

What color is the 18-1966-1 manifold? It is finished in black.

Where is the 18-1966-1 manifold manufactured? The country of origin listed for this manifold is Taiwan.

How many manifolds come in the package? One 18-1966-1 manifold is included per package.

Is the 18-1966-1 the same as Sierra's 18-1843 exhaust manifold? No, the 18-1966-1 is a distinct part number from the 18-1843 dry-joint exhaust manifold; they carry different OEM cross-references and fit different engine applications, so buyers should confirm they are ordering the part number that matches their specific engine.

Will this manifold fit an engine older than 1990? The 18-1966-1 is designated for Mercruiser 3.0L/LX engines built 1990 and newer, plus the Marine Power Engine Model E181S; fitment outside that range is not specified.

Is this a genuine Mercruiser part or an aftermarket part? The Sierra 18-1966-1 is an aftermarket manifold engineered to be fully interchangeable with the original Mercruiser equipment it replaces.