I have a 1970 Z-28 that I'm reassembling the doors on now. I installed the glass and everything works fine. I then installed the outer wiper seals for the glass and there's quite a gap between them and the glass. Do I need to get a heat gun to reform the seals tighter to the glass, or is there something I'm doing wrong here?

 

Looking at the date of your message, you may have already figured this out.
I just did the same to my 74 which I believe are the same. My problem showed up when I tried to close the door, the window was obviously in the wrong place. What happened was when I removed the window stop bracket at the bottom of the door (in order to gain access to the screws holding the rubber seal at the top) the window track roller came out of the bottom of the track when I rolled the window down. I didn't realize that and went on the adjust the placement bracketry. It still appeared to work fine rolling up because roller stayed caught on the track, but the angle was off. Once I figured it out and re-inserted the roller into the track, I had to redo all the other window placement adjustments. I hope your solution was as easy.