Most of the auto parts stores have the right pump if you just give them the year and model. Delphi seems like a good brand name. I had an Airtex E8312 and it worked well, and lasted about 40,000 miles.
https://www.oreillyauto.com/detail/c/delphi-automotive/fuel-delivery/fuel-pumps---tanks/fuel-pump/fuel-pump/83db8e3f0135/delphi-automotive-fuel-pump/dlp0/fd0035/v/a/6634/automotive-car-1975-nissan-280z?q=fuel+pump&pos=1
Looks like Rockauto will save you a lot of money on the Delphi pump. Amazon has them also. They all look about the same, a silver cylinder with some hose nipples and a piece of rubber sheet for vibration damping. You'll need to use some ingenuity to get it mounted to where you won't feel it running.
https://www.rockauto.com/en/catalog/nissan,1975,280z,2.8l+l6,1209204,fuel+&+air,fuel+pump,6256