Sierra 18-4008 Block Off Plate, OEM 60207, for 18-1958-1 and 18-1962-1 Exhaust Manifolds

The Sierra 18-4008 Block Off Plate is a replacement block off plate used to cap an exhaust manifold port when an elbow is not installed at that location. It is built for use with Sierra manifolds 18-1958-1 and 18-1962-1, sealing the manifold opening to maintain proper exhaust flow and prevent leaks. This plate is a direct cross-reference for OEM part number 60207, giving boat owners and marine technicians a straightforward way to source a replacement without going through the original equipment manufacturer.

Installation requires two 18-2833 elbow gaskets, which are not included with this plate and must be ordered separately. Proper gasket placement at the manifold-to-plate interface is essential to achieve a leak-free seal against exhaust gases and cooling water pressure. At 0.08 pounds, the block off plate is a small, lightweight component intended for straightforward bolt-on replacement during manifold servicing or reconfiguration.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-4008
• Product Name: Block Off Plate
• Weight: 0.08 pounds
• OEM Cross-Reference: 60207
• Required Gaskets: (2) 18-2833 elbow gaskets (sold separately)
• UPC: 030999563194

Fitment

• Use with Manifolds: 18-1958-1, 18-1962-1

Replaces (OEM)

• 60207

Frequently Asked Questions

What is the Sierra 18-4008 used for? It is a block off plate that caps an unused port on an exhaust manifold, used with manifolds 18-1958-1 and 18-1962-1 in place of an elbow.

Does the 18-4008 cross-reference to an OEM part number? Yes, the Sierra 18-4008 block off plate is a direct replacement for OEM number 60207.

Which manifolds does the 18-4008 block off plate fit? It is designed for use with Sierra manifolds 18-1958-1 and 18-1962-1.

Are gaskets included with the 18-4008 block off plate? No, gaskets are not included. Installing the 18-4008 requires two 18-2833 elbow gaskets, purchased separately.

How many gaskets are needed to install the 18-4008? Two 18-2833 elbow gaskets are required to properly seal the 18-4008 block off plate against the manifold.

How much does the 18-4008 block off plate weigh? The Sierra 18-4008 weighs 0.08 pounds.

Is the 18-4008 an original Sierra part or an aftermarket copy? The 18-4008 is a Sierra manufactured part sold as a cross-reference replacement for OEM number 60207.

Can the 18-4008 be used on any exhaust manifold? No, it is intended specifically for use with 18-1958-1 and 18-1962-1 manifolds rather than as a universal fit part.

What happens if I install the 18-4008 without the correct gaskets? Without the two required 18-2833 elbow gaskets, the block off plate will not seal properly against the manifold, risking exhaust and coolant leaks.

Is the 18-4008 block off plate a bolt-on part? Yes, it is designed to bolt directly onto the 18-1958-1 or 18-1962-1 manifold in place of an elbow assembly.