Sierra 18-1908K Manifold Riser Spacer KitFeatures: Packaged as a set, complete with mounting hardware; Fits: MCM V-6 carb & TBI eng. w/ 2 piece exhaust manifolds (s/n 0M614999 & below); 3" Riser Kit; Use With: Manifold 18-1952-1; Exhaust Elbow Mounting Kit 18-8554 and 18-8555; Manifold 18-1953-2 and 18-1957-1; 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; Replaces: GLM; 50310; MerCruiser Stern Drive; 93320A6; 93320A2; 93320A3; 807476A6; 93320A5; 93320A13;