Both the convertible Coronet and Satellites have the same undercarrage structures as the hardtops. They use all the same frame rails,floor pans,the peice under the rear seat,the trunk floor pans,and the inner wheel houses. The only difference is that on convertibles,they added torque boxes front and rear like on Hemi b bodies,and there are stiffining braces inside the rocker panels. other than that the only other difference is that they cut the tops of the wheel housings off and capped them with a flat panel to make room for the retracting roof. I have cut apart a few of each to turn them into Chargers. As far as I know I have never heard of any difference in the rear glass. I have never seen anyone selling B body convertible glass as Plymouth or Dodge specific. I can measure the plymouth glass,but I don't have a Dodge on hand to do so. As far as I know they are the same. Maybe someone sold you some 66/67 peices they are different. the 66/67 vert trim also looks the same,but is different lenghts.