@ 65DartCharger - Yes, all '63-'66 Hardtop doors have this same increased depth piece.
@'66 cuda - Damn if I ain't very lucky. I just disassembled my '66 cuda for paint and was wondering how to find this material as mine are worn out also. Looking at the pics, I think I'd prefer the steele rubber but I was wondering how they compare in thickness. To thick and the plastic guide on the window base won't slide up and down very easy. To thin and the window can flop around and vibrate in the the channel.
@66FormulaS273 - Were you happy with the fit and function, once reassembled, of the steel rubber product you purchased?
