There may be a different answer as to a service application. The I-6 clip, 380726-S was used from 1965 (maybe even 1964 and other earlier Fords, Falcons, etc, with I-6 170 and 200 CID engines) thru at least 1967 (there is no 1968 Engine Assembly Manual to check) and it is the service replacement for the 1966 only V-8 fuel line clip. That's the documentation part. The aftermarket, as noted, doesn't make the clip, only the 1966 V-8 fuel line bracket and its clip. I hope that makes sense.
Jim