Sierra Head Gasket 18-3876, Replaces 16.50-00204, for GM 181 CID (3.0L) Marine Engines

The Sierra 18-3876 Head Gasket is a marine engine head gasket engineered for GM 181 CID (3.0L) inboard/sterndrive engines. It seals the cylinder head to the engine block, maintaining compression and preventing coolant or combustion gases from leaking between the head and block during operation. Marine engines run under sustained load and temperature cycling that differ from automotive use, so using a gasket matched to the correct engine displacement and cylinder head design is important for a proper, lasting seal.

This head gasket is intended as a direct replacement for the OEM number it replaces, making it straightforward to identify the correct part when servicing a GM 181 CID (3.0L) marine engine. It is typically installed during head gasket replacement, cylinder head removal for valve or engine work, or as part of a broader engine rebuild or overhaul.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3876
• Product Name: Head Gasket
• Weight: 0.57 pounds
• UPC: 030999563101
• Engine Fitment: GM 181 CID Eng. (3.0L)

Fitment

• GM 181 CID Eng. (3.0L)

Replaces (OEM)

• 16.50-00204

Frequently Asked Questions

What engine does the Sierra 18-3876 head gasket fit? This gasket is designed for GM 181 CID (3.0L) marine engines, sealing the cylinder head to the engine block on that displacement engine.

What OEM part number does 18-3876 replace? Sierra 18-3876 replaces OEM number 16.50-00204.

Is 16.50-00204 the same gasket as Sierra 18-3876? Yes, Sierra part 18-3876 is the direct replacement for OEM number 16.50-00204 on GM 181 CID (3.0L) marine engines.

How much does the 18-3876 head gasket weigh? The Sierra 18-3876 head gasket weighs 0.57 pounds.

When would I need to replace this head gasket? A head gasket like the Sierra 18-3876 is replaced any time the cylinder head is removed for service, or if the existing gasket has failed and is leaking coolant or compression on a GM 181 CID (3.0L) engine.

Does this gasket fit other GM engine displacements, like the 305 or 350? No, the 18-3876 is specific to the GM 181 CID (3.0L) engine; other displacements use a different Sierra part number.

Is this a genuine Sierra part or aftermarket? The 18-3876 is a Sierra-branded head gasket, sold under Sierra's own part number for GM 181 CID (3.0L) marine engines.

What is included when I order part 18-3876? Ordering Sierra 18-3876 gets you one head gasket sized for a GM 181 CID (3.0L) marine engine cylinder head.

Can I identify this gasket by the number 16.50-00204 when searching? Yes, searching by 16.50-00204 will match this gasket, since Sierra 18-3876 is listed as its replacement.

What is the UPC for this head gasket? The UPC for the Sierra 18-3876 head gasket is 030999563101.