I believe so, Your car should have threaded bosses welded in up above the window
I "thought" I knew that some 68's had it and some did not. Years ago I started a discussion (about my 67) after seeing the option listed in a brochure
LOL from 2012
67 Dart shoulder harness anchor?
This is what "got me on it" the 67 accessories cat.
The 1970 Hamtramck Registry - 1967 Mopar Line of Accessories Catalog Slideshow