Sierra 18-1908K Manifold Riser Spacer Kit for MerCruiser Stern Drives

The Sierra 18-1908K Manifold Riser Spacer Kit is a complete 3-inch riser extension system designed for MerCruiser V-6 marine engines with 2-piece exhaust manifolds. These extensions provide critical extra height to prevent water from traveling back into the riser when throttling down, while also offering added clearance for exhaust hose routing.

Key Features:

• Engineered for GM-based V6 marine engines (229 and 262 cu.in.) with 2-piece exhaust manifolds
• Machined mating surfaces eliminate additional preparation for proper sealing
• Each riser extension is leak tested prior to painting to ensure quality
• Uniform wall thickness created through special casting techniques
• Primed and painted for durability and corrosion protection

Complete Kit Includes:

• Two 3-inch riser spacer extensions (port and starboard)
• Threaded rods and mounting hardware
• Gaskets and pipe plugs
• Ready to install out of the box

This kit replaces OEM part numbers 93320A13, 93320A6, 93320A5, 93320A3, 93320A2, and 807476A6. Compatible with MerCruiser models 185 and 205 (V-6 carbureted and TBI engines with serial numbers 0M614999 and below). Sierra engineers parts to meet or exceed manufacturer specifications, backed by SeaStar Solutions Limited Two-Year Warranty.