For 1967, try faxonautolit.com (located in Riverside CA). Be aware that the Service Manual was introduced in 1966, then for 1967, Ford issued a suppliment.

1966 Comet/Fairlane/Ranchero/Mustang Service Manual: $57.00 available from helminc.com.

This is genuine Ford and brand new. Helm has printed all of FoMoCo's literature since the 1940's.