Align parts while reducing wear with a Sierra Shim for OMC Stern Drive and Cobra Stern Drives. For 50 years Sierra has been producing parts engineered to meet or exceed the specifications of marine engine manufacturers and has gained the confidence of engine manufacturers and boat builders to a point of supplying them with OEM parts. Boaters and technicians can be assured a Sierra part will fit right the first time and restore function to OEM specifications. Key Features Engineered to meet or exceed OEM specifications Replaces OMC Stern Drives, Johnson/Evinrude Outboards, and GLM The Sierra Engine Parts Selector We offer a wide variety of other engine parts manufactured by Sierra. To see if we have the part you need, see ourEngine Parts Selector, where you can search by engine make, serial number and model or year of manufacture.