Sierra 18-1908K Manifold Riser Spacer Kit for MerCruiser V6 V8 Engines

The Sierra 18-1908K Manifold Riser Spacer Kit provides the extra height to prevent water from traveling back into the riser when throttling down and offers added clearance for exhaust hose routing on marine inboard installations. This 3-inch riser extension kit is designed for MerCruiser stern drives with GM-based V6 and V8 engines including 4.3L, 5.0L, 5.7L, 305, 350, 454, 502, 7.4L, and 8.2L applications with 2-piece exhaust manifolds.

Key Features:

• Machined mating surfaces eliminate additional preparation to establish a proper seal
• Each riser extension is leak tested prior to paint to ensure quality
• Special casting techniques create risers with uniform wall thickness
• Complete kit includes extensions, threaded rods, fasteners, gaskets and plugs for both port and starboard sides
• Backed by SeaStar Solutions Limited Two-Year Warranty

Kit Includes:

• Manifold Riser Spacer 18-1908
• Pipe Plug 18-4258
• Pipe Plug 18-4263
• Exhaust Elbow Gasket 18-2849-1
• Exhaust Elbow Gasket 18-0897
• Exhaust Elbow Gasket 18-0672

Sierra engineers parts to meet or exceed manufacturer specifications, ensuring reliable performance in demanding marine environments. This kit is ideal for replacing corroded risers or combating backflow and clearance issues during new installations.

Replaces OEM Numbers: MerCruiser 93320A6, 93320A2, 93320A3, 807476A6, 93320A5, 93320A13; GLM 50310