Fits:  Sierra 18-3574 Circulating Water Pump GM (Chevy) 7.4-Liter and 8.2-Liter (454 and 502 cu.in.) Big Block V-8 Engines late model with composite timing covers. Bi-directional Brass Impeller, Stainless Steel Backing Plate, Includes Mounting Gaskets. Fits both LH and RH Rotation engines. 1-year limited warranty.
Replaces Mercruiser 850454, 8504541, Mallory 9-42604