water pump assembly for a 1965 johnson seahorse 18 hp question

[Sea Nimph Captain]

I purchased a water pump rebuild kit for the lower unit and It came with a shaft seal that im not familiar with. it is about a half inch long and has two rubber bumps that come out from equal opposite sides that appear to be for locking it in place. does this go on the top or bottom of the pump assembly. there is a seal on the bottom between pump and gear case but that seal has a brass ring on top of it and seems smaller than this one. It seems like it would go on the top but there wasnt one on top when I opened it up. Or does this seal only apply to a model other than mine? Thanks for any help

[billsfw]

For the water tube on top of the pump housing?

[kbait]

Indeed. It's the replacement grommet for the top of the waterpump housing where the water tube connects. Your original is still in the housing, and would likely work fine, but you may as well swap 'em out since you have a new one. I usually just replace the impeller alone if housing and plate look good..