You can put every piece of an F3 onto an F2. the F3 lowers and uppers must be installed together though, as they're slightly longer than F2 bodywork, the F3 tail will pretty much bolt on, and I think you need the F3 fairing stay for the upper as well.
the 97-98 f3 tail will bolt right on the f2 for sure, you need all the tail peices taillight and the seat i think. Looks alot better imo.
Im in the process of putting a f2 together i have everything minus the right side and insp panel, and the right side upper as far as plastics. If anyone has an extra set and needs some cash let me know