Sierra 18-1843 Dry Joint Exhaust Manifold, Replaces 27-864850A02, Fits 4.3L 5.0L 5.7L 6.2L

The Sierra 18-1843 is a dry joint style exhaust manifold built for 4.3L, 5.0L, and 5.7L / 6.2L marine engines that use the dry joint manifold and riser exhaust system. Unlike wet joint manifolds, the dry joint design keeps the exhaust manifold and riser joint isolated from raw cooling water, which helps reduce the corrosion and joint failure common to older wet joint setups. This manifold is engineered to meet or exceed the performance of the original equipment part it replaces, and it is built to hold up to the heat cycling, vibration, and saltwater or freshwater exposure typical of inboard and sterndrive engine compartments.

The 18-1843 is designed to be used together with the 18-1842 manifold and the 18-1845 riser as part of a complete dry joint exhaust manifold and riser system, so buyers replacing one component of this system can order the matching parts with confidence that they are built to work together. This manifold is a direct fit replacement for the OEM part numbers listed below, making it a straightforward swap for engines that originally used those manifolds.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-1843
• Product Type: Dry Joint Exhaust Manifold
• Style: Dry Joint
• Engine Fitment: 4.3L, 5.0L, 5.7L, 6.2L (dry joint manifold and riser system)
• Used With: 18-1843 and 18-1842 manifolds, 18-1845 riser
• OEM Cross Reference: 27-864850A02, 27-864547A1
• Weight: 49 pounds
• UPC: 808282359423

Fitment

• 4.3L, 5.0L, 5.7L, 6.2L engines using the dry joint exhaust manifold and riser system
• Used with 18-1843 and 18-1842 manifolds and 18-1845 riser

Replaces (OEM)

• 27-864850A02
• 27-864547A1

Frequently Asked Questions

What engines does the Sierra 18-1843 exhaust manifold fit? The Sierra 18-1843 fits 4.3L, 5.0L, 5.7L, and 6.2L marine engines that use the dry joint exhaust manifold and riser system.

Is the 18-1843 a direct OEM replacement? Yes, the 18-1843 is a direct replacement for OEM manifolds 27-864850A02 and 27-864547A1, so it installs in place of the original part without modification.

What is a dry joint exhaust manifold, and why does it matter? A dry joint exhaust manifold, like the Sierra 18-1843, keeps the manifold-to-riser joint separated from raw cooling water, which reduces the corrosion and joint failure that affect older wet joint exhaust designs.

Does the 18-1843 need to be ordered with any other parts? The 18-1843 manifold is designed to be used together with the 18-1842 manifold and the 18-1845 riser as part of one dry joint exhaust system, so matching those parts is recommended for a complete rebuild.

How much does the Sierra 18-1843 weigh? The Sierra 18-1843 exhaust manifold weighs 49 pounds.

What OEM part numbers does the 18-1843 cross reference to? The 18-1843 crosses over to OEM numbers 27-864850A02 and 27-864547A1.

Is the Sierra 18-1843 covered by a warranty? Sierra parts, including the 18-1843 manifold, are backed by Sierra's customer satisfaction warranty covering defects in workmanship and materials.

Can the 18-1843 be used on both 5.0L and 5.7L engines? Yes, the 18-1843 is built to fit 4.3L, 5.0L, 5.7L, and 6.2L engines using the dry joint manifold and riser configuration.

Does the 18-1843 replace a wet joint manifold? No, the 18-1843 is specifically a dry joint style manifold and is intended for engines already set up with a dry joint manifold and riser exhaust system, not a wet joint system.

What comes with the Sierra 18-1843? The Sierra 18-1843 is supplied as a single dry joint exhaust manifold; the matching 18-1842 manifold and 18-1845 riser are separate parts sold individually.