This is only the flare portion of the quarter panel (rear) that can be used as an over fender bonded to your existing metal quarter panel.
It can be used to attach to other quarter panels, for example, the 280ZX. However, the metal panel will have to be trimmed for tire clearance.
Matching the profile would be a little trickier than on the fender, as the trim line will probably result in an edge that meets the metal at more of an angle than flat. So you may have to do a narrow layup of fiberglass across that edge to blend to the metal.
The finished width is approximately 4" wider than your stock fender, depending on exactly how much you trim the fiberglass.