Sierra Head Gasket 18-3877 for GM 262 (4.3L) CID Marine Engines, Replaces 3854299

The Sierra 18-3877 Head Gasket is a replacement head gasket engineered for GM 262 (4.3L) CID marine engines. It seals the mating surface between the cylinder head and engine block, maintaining proper compression and preventing coolant or combustion gas leaks between the two components. Installing a correctly fitted head gasket is a critical step whenever a cylinder head is removed for service, replaced, or resurfaced, since reusing a worn gasket can lead to compression loss, coolant intrusion into the cylinders, or oil leaks.

This gasket is finished in white and is sold as a single unit, ready to install as a direct replacement during a head gasket job on a supported GM 262 (4.3L) CID engine. Sierra parts are built to meet or exceed the specification of the original equipment part they replace, giving boat owners and marine technicians a dependable option when servicing GM-based marine engines.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3877
• Product Type: Head Gasket
• Color: White
• Weight: 0.45 pounds
• UPC: 030999563118
• Quantity: 1 gasket per unit
• Engine Fitment: GM 262 (4.3L) CID Engine

Fitment

• GM 262 (4.3L) CID Engine

Replaces (OEM)

• 3854299
• 912227
• 914930

Frequently Asked Questions

What engine does the Sierra 18-3877 head gasket fit? The Sierra 18-3877 head gasket is designed for GM 262 (4.3L) CID marine engines.

Is the 18-3877 a direct replacement for OEM part 3854299? Yes, the Sierra 18-3877 head gasket is a cross-reference replacement for OEM numbers 3854299, 912227, and 914930.

What color is the 18-3877 head gasket? It is finished in white.

How much does the 18-3877 head gasket weigh? The Sierra 18-3877 head gasket weighs 0.45 pounds.

How many gaskets come in one order of 18-3877? Each order includes one Sierra 18-3877 head gasket.

Will this gasket work on any V-8 marine engine? No, the Sierra 18-3877 is specified for GM 262 (4.3L) CID engines; a different Sierra part number is required for other GM engine displacements.

Does Sierra's 18-3877 meet original equipment quality standards? Sierra states that this head gasket meets or exceeds the specification of the original equipment part it replaces.

What is the UPC for the Sierra 18-3877 head gasket? The UPC for the 18-3877 head gasket is 030999563118.

Do I need to replace both head gaskets if my engine has two cylinder heads? The 18-3877 listing covers a single head gasket for a GM 262 (4.3L) CID engine; check how many are needed for your specific engine build before ordering.

What OEM numbers does 18-3877 cross-reference to? It cross-references to OEM numbers 3854299, 912227, and 914930.