They're both. I've had both. The original IBZUSA with no "F" lettering after it is not F spaced. It's regular spaced. Although I've never seen an F2 that wasn't F spaced come to think of it, but in 1989 they just came out with the F series and it's possible. All your F3's should be F spaced, and I have had F1's that were F spaced, but they tout that as a neck pickup, too and so I imagine it was made both ways, maybe not, though, because I seem to remember taking one out of an S that was F spaced.