give it a day or so and someone can tell you for sure, but...
classic industries online catalog specifies a different part # for the quarter window glass between coupe and 'vert, but they do not specify a difference in the door glass.
birdquest68 is right, be real careful ordering glass for that convertible. I think only the main door glass pieces are the same, all others are slightly off and not useable for your bird. Of course all seals and trim are slightly different as well. Don't get ripped off by some glass-geek that says otherwise!
'68 428 HO M3 Monster, 4-on-the-floor! Need I say more?