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Full Flow Elbow Gasket – Fits MerCruiser V-6 & V-8 (Replaces 864547A02, 864547A1)

Regular price $28.00
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Full Flow Elbow Gasket – Fits MerCruiser V-6 & V-8 (Replaces 864547A02, 864547A1) 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 Full Flow Elbow Gasket – Fits MerCruiser Dry Joint V-6 & V-8 is designed for MerCruiser engines using a dry joint exhaust system, specifically covering GM V-6 and V-8 models (4.3L, 5.0L, 5.7L, 6.2L) manufactured in 2002 and newer. It ensures a proper seal between the exhaust manifold and the riser in standard cooling systems.

It serves as a direct replacement for MerCruiser part numbers 27-864547A02 and 27-864547A1, and is a cross-reference for Sierra 18-0721.

  • Engineered for dry joint exhaust connections.
  • Designed for standard cooling systems with a full flow configuration.
  • Made from durable composite gasket material to withstand the marine environment.

Part Number Matrix

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

Brand Part Number Notes
MerCruiser 27-864547A02 Original Equipment Manufacturer
MerCruiser 864547A02 Original Equipment Manufacturer
MerCruiser 27-864547A1 Original Equipment Manufacturer, Superseded
MerCruiser 864547A1 Original Equipment Manufacturer, Superseded
Sierra 18-0721 Aftermarket Interchange

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For MerCruiser applications, this gasket fits specific V-6 and V-8 engines with dry joint exhaust manifolds from 2002 forward.

Brand Model Rated HP Stroke Years OEM Part No. Notes
MerCruiser 4.3L Various 4-Stroke 2002–newer 27-864547A02/A1 For Dry Joint Manifold and Riser
MerCruiser 5.0L Various 4-Stroke 2002–newer 27-864547A02/A1 For Dry Joint Manifold and Riser
MerCruiser 5.7L Various 4-Stroke 2002–newer 27-864547A02/A1 For Dry Joint Manifold and Riser
MerCruiser 6.2L Various 4-Stroke 2002–newer 27-864547A02/A1 For Dry Joint Manifold and Riser

Technical Specs

Product Type
Exhaust Elbow Gasket (Full Flow)
Installation
Dry Joint
Fuel Type
Gas
Connection
Between exhaust manifold and riser
Housing Material
Composite Gasket Material
Dimensions
7.87 in × 4 in (200 mm × 101.6 mm) with 7/16 in mounting holes
Other Technical Attributes
For standard cooling with full flow configuration

What’s in the Box

  • 1 x Full Flow Elbow Gasket (Replaces 27-864547A02, 27-864547A1)

Installation Notes

  1. Ensure the engine is cool and disconnect the battery for safety.
  2. Drain the engine coolant to prevent spills.
  3. Unbolt and carefully remove the exhaust riser (or elbow) from the exhaust manifold.
  4. Thoroughly clean both mating surfaces, ensuring all old gasket residue and corrosion are gone.
  5. Position the new dry joint gasket correctly over the mounting studs on the manifold.
  6. Reinstall the riser, ensuring it aligns perfectly without forcing it.
  7. Tighten the mounting bolts in a star or crisscross pattern to the manufacturer's specified torque.
  8. Refill the cooling system, reconnect the battery, and start the engine.
  9. Carefully inspect the gasket area for any signs of water or exhaust leaks.

Troubleshooting & FAQ

How do I confirm this gasket fits my engine?

This gasket is for MerCruiser V-6 & V-8 engines (4.3L, 5.0L, 5.7L, 6.2L) from 2002 and newer with a "dry joint" exhaust system. Please verify your engine model and year against the compatibility table above. Visually comparing your old gasket to the product images is also recommended.

What is a "dry joint" exhaust and why is it important?

A "dry joint" exhaust system is a newer MerCruiser design that improves the seal between the manifold and riser to prevent water from entering the engine. This gasket is specifically made for that design and will not work with older, "wet joint" systems.

What are common signs of a failed elbow gasket?

Symptoms of a bad gasket include visible water leaks (especially when the engine is running), rust stains around the joint, engine overheating, or water intrusion into the engine cylinders, which can cause catastrophic failure.

Is this a "full flow" or "restricted" cooling gasket?

This is a full flow gasket, used in standard cooling systems. Do not use this where a restricted or blocked gasket is specified, as it will alter cooling performance.

Should I use sealant on this gasket?

No. Dry joint gaskets are designed to be installed dry. Using gasket sealant or cement can interfere with the seal and cause premature failure. Always install on clean, dry surfaces.

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.

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