Two discussion points resolved via pictures on this page:  Diablo vs. Z headlights and 90-94 Z vs 95-96 Z headlights.

In this first set, I hope to shed some light on the whole Diablo vs. 300ZX headlight discussion.  At a recent Hot Import Nights in Dallas, I had the opportunity of taking pictures of a Diablo VT (95?) and a 300ZX (95).  Although you can not really read the numbers imprinted on the headlights themselves, they are in fact the exact same headlights!  Down to the beam dispersement pattern on them (i.e. the refractive lines).  The Diablo, though, had a thin carbon-fiber strip running along the top of the headlights to hide the word "Nissan"!  Here are the pics:

Now, this second set compares 94 vs. 95 headlights (left and right of the picture below, respectively).  There are a couple of differences.  (1) Can be found in the left mid-quadrant section.  Look closely and you will see.  (2) Look in the middle; the left set says H83 (94) and the right set says H92 (95).