DR Legend flatwounds are my favorites so far for my 1970 Starfire (my main player) which are the "short scale" set. Length-wise they fit pretty well, though sometimes you you have to trim the silk windings back just a tad to clear the nut. Only takes an extra minute or two with a razor. I can't recall every set I've tried on this bass, but definitely Fender flats, GHS brite flats, Rotosound, D'Addario Chromes, and Thomastik Infelds.
My 1967 Starfire has LaBella black nylon tapewounds on it, "medium scale" set fits perfectly as others have mentioned. For some reason this Starfire likes lower tension strings more... it does have a noticeably slimmer neck and thinner fretwire, so that might have something to do with it. Thomastik Infeld flatwounds were pretty nice on this one though they had the same issues that I have encountered with every TI bass flatwound set that I've tried, which is a noticeably thinner/weaker sounding E string and the fact that they never seem to feel equally smooth from string to string. I can't really explain it, as I love both their electric guitar and classical guitar flatwound offerings and have never had similar issues with those sets.