11/73 260Z

I'm about to under go this project but want to be clear on the alternator I should buy. I'd like to get a 90 amp that works on the same brackets as my factory 11/73 260Z has. I saw mention of a Maxima and a 240sx. Can someone elaborate on the year and will the same alt belt work on these? I know my questions may be a little too specific but I want to have everything in order before I dive in. Thanks, Chris