if everything being of equal shape ? go with the '96
88-89 frames are missing the brackets for the metal heel guards on the angled frame section from down near the swingarm bolt up to the rear seat section.
90-02 have those heel guard mounts, and some have some random mounts for reflectors in states that required them, I've only ran into this once in all the blasters I've had or worked on, but those don't effect anything.
88-02 are nearly identical besides those heel guard mounts and use the same platsics and CDI and TORS units mount under the hood
03-06 frames added ..... rear brake master cylinder and brake light switch mount, different CDI/TORS mount under the hood, built in headlight mount, and different front hood mount
I started with a 92 blaster, swapped everything to an 06 frame for the title and hydro brake mounts, and now on an 03 frame after breaking the 06.
so it is possible to swap everything from all years, with some mounts fabbing required to go to the newer 03+ frames when using the pre 03 electronics and plastics.
it;s also possible to go backwards, 03+ parts onto pre 03 frame, but not sure who would do that and lose the hydro brake mounts.