Sierra 18-1937 Riser Reservoir for 3.7-Liter Mercruiser with Aluminum Manifold. Direct replacement for Mercruiser riser reservoir number 98562A6. (Note, mounting bolts go thru body of riser and are 4" long). Later Production, FITS MERCRUISER ALUMINUM MANIFOLD 93174A4, 816219A1 and 816219A5. Please note: the elbow/reservoir is cast iron but the manifold is aluminum. 1-year limited warranty.