It depends on the build date of the car- while the model year, say '65, started in October of '64, the federal regs didn't kick in 'til the beginning of the calendar year. Seat belts were a requirement in the mid- '60's, my dad's '65 Vista Cruiser, '63 Corvair and '64 F-85 all had front belts. They became a requirement for the rears in '66. Dad also had a '68 Ranchero that he bought new, and since it was built before 01-01-'68, it did not have the federally mandated shoulder belts. His '69 Fairlane wagon (which, as a fourteen year old kid, I got to help him order it- he nixed my idea for the 390 ), had seat belts from stem to stern, shoulder harnesses for the front and the federal requirement for '69- head rests.