78 Johnson 115 Water pump. what's this all about? (pictures)

[Kebm]

I have an 86 Evinrude 110 that has at some point had the lower unit replaced with a 78 Johnson 115 lower unit. I ordered the water pump kit for the 86 110 and needless to say the impeller is incorrect. The impeller that came in the kit has the plastic wedge key drive and the original impeller has a woodruff key drive. I am going to purchase a new impeller but the housing seems to be the same but a little different. The old housing has an oil seal that is pressed into the top of the housing and the new kit does not have one or a place for one. Is this the right housing? I have done some looking on the internet at some of the water pump kits that are for the 78 Johnson 115 they appear to be identical to the kit that I have other than the impeller.

This is a Mallory water pump kit. Are the Mallory impellers any good? would it be worth investing into an OMC impeller?

Thank you in advance for all of the advice. I would be dead in the water without this forum.

Check out the attached photos of the two housings.

[ezeke]

You can use the impeller that came with the newer pump if you still have the metal key that goes with your driveshaft. Otherwise the newer pump is generally a better pump.