Sorry if this has been cover but searching for "butyl rope" and got hits for everything but. So, what size butyl rope is required for setting rear glass in 74 challenger?

Thanks
Scott

ANY 3/8" should work, as long it fits into the channel, it doesn't have to be any specific size or type. I think I used close line on my dart.

I usually buy both the 3/8 and 5/16 so I'm not screwed the day I'm installing glass, you can always return what you don't use/need....but when the stores closed and you need the other size, your screwed, buy both, never fails, you always need the size you didn't buy...DAMHIK

Just a warning, if its to thick the trim won't go on.

The last E Body I installed the windshield and back glass in I used 5/16 in.

I did glass work during this era.. We used 3/8 for the WS and ALWAYS used 5/16 ( or even 1/4" ) on the back glass and any glue in side lites.. As said above, you will have issues with the trim using a 3/8 "kit" on the backglass....

Set it on a warm day, or heat it a little in the microwave ( seems as if 30 seconds was enough ), or hang a radiant heater over it after install and after it warms push the glass into the kit a little further..

Thanks for the help, guys!