ever get an answer? i wrote Lendendary Interiors and they said F-body seats were the same across lines (frames and springs). '67-8 were different from '69s, though... i plan on attempting covering '67 firebird seats w/ headrests w/ '68 deluxe foam and covers. I imagine I will have to buy the '69 headrest covers and see what happens, even though i know they are different sizes. the cure may be additional material. but i won't be doing this any time soon...