67 or 68 barracuda parts

I think you asked two separate questions: deck lid, and hood.

67 & 68 hoods are the same (essentially), with twin bulges and chrome inserts, which are interchangeable. The 69 hood is flat, with no inserts, and with a raised "beak" at the center front, which won't match up with a 67/68 nose panel.

67, 68 & 69 deck lids are the same basic unit, but they are drilled completely differently for the trim panels. A 69 trim panel covers the entire surface, so extra holes wouldn't be noticed, but 67 or 68 decklid trim both expose certain areas of sheet metal, which would be full of holes if you were trying to use a different year trim set. So the bottom line is, it isn't worth your time to mess around filling dozens of small holes and drilling new ones -- just swap for the correct year.