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

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

This intake/exhaust manifold gasket is designed for Mercury MerCruiser 4-cylinder 120HP (2.5L) and 140HP (3.0L) engines from 1983–1995. It serves as a direct replacement for multiple OEM and aftermarket part numbers, ensuring a precise seal between the cylinder head and the intake/exhaust manifold.

This part directly replaces: Mercury/Quicksilver 27-96429, Sierra 18-2801, and GLM 32180.

• Installation Location: Mounts directly between the cylinder head and the intake/exhaust manifold.
• Engine Compatibility: Specifically for use on non-LX 4-cylinder engines.
• Fuel Type: Designed for gasoline-powered engines.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x Manifold Gasket (27-96429)

Installation Guide

1. Safety First: Disconnect the battery terminals and ensure the engine is cool to the touch.
2. Drain Coolant: Drain the engine coolant from the block and manifold to prevent spills.
3. Remove Components: Detach any components obstructing access to the manifold, such as the carburetor, fuel lines, and linkages.
4. Unbolt Manifold: Carefully and evenly loosen and remove the bolts securing the intake/exhaust manifold to the cylinder head.
5. Clean Surfaces: Remove the old gasket and thoroughly clean any residual gasket material or corrosion from both the cylinder head and manifold mating surfaces. A clean, smooth surface is critical for a good seal.
6. Position New Gasket: Place the new gasket into position, ensuring it is correctly aligned with all bolt holes and ports.
7. Reinstall Manifold: Re-mount the manifold and hand-tighten the bolts.
8. Torque Bolts: Tighten the manifold bolts to the manufacturer's recommended torque specification, following the correct sequence to ensure even pressure.
9. Reassemble: Reinstall all previously removed components and reconnect fuel lines.
10. Final Checks: Refill the cooling system, reconnect the battery, and start the engine. Carefully check for any exhaust, fuel, or coolant leaks around the gasket area.

Troubleshooting & FAQ

How do I confirm this gasket fits my engine?

This gasket is for MerCruiser 120HP (2.5L) and 140HP (3.0L) 4-cylinder engines from 1983-1995. To ensure a perfect match, check your engine's serial number against the ranges in the "Compatible Engine Models" table above. Crucially, this part is for non-LX models only.

What are the signs of a failed manifold gasket?

Common symptoms include a hissing or ticking sound from the engine bay, visible exhaust or coolant leaks near the manifold, reduced engine performance, rough idling, or overheating due to a coolant leak.

Is this for Chevy 153/181 CID engines?

Yes, this gasket is used on the GM/Chevrolet 153 cubic inch (2.5L) and 181 cubic inch (3.0L) 4-cylinder engine blocks that MerCruiser marinized for these models.

OEM vs. Aftermarket?

This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

How fast do you ship and how much does it cost?

We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

What is your warranty and return policy?

This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.