Hello All,<br /><br />I'm in the process of replacing my burnt out 1980 Johnson 70HP lower unit with a lower unit that was apparently from a 1982 70HP engine. The 1982's water pump impeller was in awful shape, and I had to cut it off to get it off of the driveshaft. When I did this, I noticed that the impeller and driveshaft were quite different between the two units, in that the 1980 shaft had a flat indented spot and used a small metal rod for a key, whereas the 1982's shaft protrudes in ridges that form a key that the impeller fits onto. <br /><br />However, when shopping for impellers, everyone is trying to sell me the same item regardless of whether it is a 1980 or 1982 lower unit, so I'm reluctant to buy just to have to ship it back. An impellar that would fit my 1980 unit would definitely not fit my 1982 unit. What's going on here, and how do I find the impeller I need? <br /><br />Thanks much,<br />Mark