Check w/ Jim Cook Racing first, I don't think they still sell it but I could be wrong. You may also want to check w/ <http://www.showcars-bodyparts.com/240z.html>
They claim to have it but I'm not sure. You like that kit? I ask because I have the original car that the molds for that kit were taken from. Jim Cook himself took the molds. Unfortunately he died in a race accident, however his wife still runs the buis. The installation may require a bit of work. the headlights will also be changed to square type. On my original car the headlight area was covered over to make a smooth nose. However this means my car has no headlights. You can get a look at my car on www.zdriver.com. look in the "Rides" section for a '75 280 under the name "TheCaZ" Good luck.