Having all the parts handy can make changing an impeller easier. Changing an impeller can be straight forward or it can be a bear. Either way having all the needed parts will help speed up the process. Sierra packages impeller kits to save you time; all of the research and sourcing of individual parts has been done. Each impeller, water pump shaft seal, impeller plate and O-ring of the kit is engineered to meet or exceed OMC specifications. We recommend having a spare impeller (Sierra p/n 18-3085) for unexpected failures caused by debris or clogged intakes. Key Features Engineered to meet or exceed OEM specifications Kit includes impeller, impeller plate, water pump shaft seal and O-rings Fits many OMC sterndrive applications manufactured between 1964—1986 Replaces Mallory p/n 9-45284 Does not work with Cobra models. The Sierra Engine Parts Selector In addition to impeller kits, 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.