I have a 1/71 production date 240Z that has major front end damage so I'm shopping around for a front clip.  My question is what differences are there between the different years and when were those differences?  Example, I'm looking at a 6/71 build and wondering if there were changes made from 1/71 to 6/71?  My 1/71 has all the expected series I items such as the latching fuel door, no vents in the rear quarter/pillar, etc.

The only things that I can think of that could be different are when they changed the supports under the top of the fenders that the little foam pads sit on from one to two, and the metal tabs for the wire harness down the length of the passenger rail changed from one to a double tab. I am not sure when those changes occurred and neither will be a problem.