68 valiant …. What years and Model drip rail trim fit

Dart has 3" longer wheelbase, and that space was inserted in the rear footwell, which implies that it has a 3" longer roofline. The Valiant 2dr hardtops were the same as Darts, and the late 4dr sedans were the same, but I think your 67-69 2dr/4dr post cars are going to be different. But I don't know that for a fact. On the other hand, you could probably just cut off the Dart drip rail trim at the A pillar, where it is hidden by the corner piece.