Intake/Exhaust Manifold Gasket – Fits MerCruiser 120/140/2.5L/3.0L (Replaces 27-96429)

$16.49

Shipping calculated at checkout.

Intake/Exhaust Manifold Gasket – Fits MerCruiser 120/140/2.5L/3.0L (Replaces 27-96429) is backordered and will ship as soon as it is back in stock.

Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This replacement Intake/Exhaust Manifold Gasket – Fits MerCruiser 120/140/2.5L/3.0L Engines (Replaces 27-96429) is designed for Mercury MerCruiser 4-cylinder 120HP (2.5L) and 140HP (3.0L) engines manufactured between 1983 and 1995. It provides a reliable seal between the cylinder head and the intake/exhaust manifold on non-LX models.

This part is a direct interchange for Mercury/Quicksilver 27-96429, Sierra 18-2801, and GLM 32180.

Installs between the cylinder head and intake/exhaust manifold.
Engineered for use in gasoline marine engines.
Includes one manifold gasket as shown.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Mercury/Quicksilver	27-96429
Sierra	18-2801
GLM	32180

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For MerCruiser applications, verify your engine's serial number falls within the specified range for a correct match.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
MerCruiser	120	120	4-Stroke	1983–1986	27-96429	Serial Range: 6229718-0B531853
MerCruiser	140	140	4-Stroke	1983–1986	27-96429	Serial Range: 6229718-0B450800
MerCruiser	2.5L	120	4-Stroke	1987–1989	27-96429	Serial Range: 0B531854-0C853255
MerCruiser	3.0L	140	4-Stroke	1987–1989	27-96429	Serial Range: 0B450801-0C856558
MerCruiser	3.0L	140	4-Stroke	1990–1995	27-96429	Serial Range: 0C856559-0F353099

Technical Specs

Product Type: Intake/Exhaust Manifold Gasket
Installation: Between cylinder head and intake/exhaust manifold
Fuel Type: Gasoline
Connection: Bolt-through mounting
Housing Material: Gasket material
Housing Color: Black
Warranty: Varies by manufacturer
Other Technical Attributes: For use on non-LX 4-cylinder engines

What’s in the Box

1 x Manifold Gasket (Replaces 27-96429)

Installation Notes

Disconnect the vessel's battery and allow the engine to cool completely.
Drain the engine block and manifold cooling system to prevent spills.
Carefully label and remove any components obstructing access to the manifold, such as fuel lines, wiring, or linkages.
Systematically loosen and remove the manifold mounting bolts.
Gently pry the manifold away from the cylinder head and remove the old gasket.
Thoroughly clean both the cylinder head and manifold mating surfaces. Ensure they are free of old gasket material, rust, or debris.
Position the new gasket correctly over the alignment dowels on the cylinder head.
Reinstall the intake/exhaust manifold, ensuring it is properly seated against the gasket.
Hand-tighten the bolts, then torque them to the manufacturer's specified sequence and values.
Reinstall all previously removed components.
Refill the cooling system, reconnect the battery, and start the engine. Check for any exhaust or coolant leaks around the gasket area.

Troubleshooting & FAQ

How can I confirm this gasket fits my specific engine?

This gasket is for MerCruiser 4-cylinder 2.5L and 3.0L engines (non-LX models) from approximately 1983 to 1995. The most reliable way to confirm fitment is to check your engine's serial number against the ranges listed in the compatibility table.

What are the signs of a failing intake/exhaust manifold gasket?

Common symptoms include a visible exhaust or water leak around the manifold/cylinder head joint, a loud ticking or hissing noise from the engine bay that changes with engine RPM, reduced engine performance, and overheating if coolant is leaking externally or internally.

Is this gasket compatible with both 120HP and 140HP models?

Yes, it is designed for both the 120HP (2.5L) and 140HP (3.0L) 4-cylinder GM-based MerCruiser engines within the specified year and serial number ranges.

Do I need to use any sealant with this gasket?

Generally, this type of gasket is designed to be installed dry. Applying sealants can sometimes cause the gasket to slip or fail prematurely. Always follow the specific instructions in your engine's service manual.

What material is the gasket made from?

This is a high-quality aftermarket gasket made from durable composite materials designed to withstand the heat and pressure of the marine exhaust system, similar to the original OEM part.

The compatibility table mentions "non-LX" models. How do I know if my engine is an LX model?

LX models are typically higher-performance versions. The surest way to know is by checking your engine's model designation and serial number. This gasket is specifically for the standard, non-LX 3.0L engines.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

Payment & Security

Payment methods

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.