Will an L24 water pump fit in an L28?

It's the same thing.

Why?

Are you just replacing it, or something else?

Yup! just replacing it.

I have a '73 S30 (I hope that's right) with an L28 in it. Someone saw my car and handed me a box of parts (most new except for the SU carbs which I've begun to study/disassemble so I can better tune/address the SUs in my car). A water pump was included in the box, and I was thinking that I might need a timing chain and sprocket replacement so why not do the water pump too.

I'm glad to learn that they are the same. Thanks, TomoHawk and ED, for your responses to my question.

The Doctor