This may be old news for many, but I was so excited to find this through a search on the 240SX.org archives.
Go to
www.nissan.co.za
click on "owning" (on mid upper right)
click on "parts"
click on "passenger vehicles"
on the drop down menu, pick "200SX (SR20DET)"
after this, use the scroll down menus to navigate.
When you get the nice diagrams, you can click on the numbered part, and then the Nissan part number will be displayed. Very nice. I wish Nissan USA would do this for their US vehicles.
Enjoy,