This is only the flare portion of the fender (front) that can be used as an over fender bonded to your existing metal fender.
It can also be used to attach to other fenders, for example, the 280ZX. However, the metal panel will have to be trimmed for tire clearance.
The profile is a little different on the ZX vs the Z, but there's plenty of extra material to allow you to trim and/or fill for a precise fit to your liking.
The finished width is approximately 2.5" wider than your stock fender, depending on exactly how much you trim the fiberglass.