Another Mopar Off My Bucket List - Barracuda Fastback

The guys in the videos struggled for a couple reasons.
The butyl sealant they used packaged in a caulking type tube is meant
to be used with a non rubber gasket type install. For later model mid 70s cars.
With the correct pump can of sealant with the needle application tip you can
inject the buytl after the glass is set into the car. No mess and it will get it down
where it needs to be. The needle will inject sealant on the glass & body side of the rubber seal as that is what it is designed to do for our older model cars.
Second they used nothing as a lubricant on the rubber seal and cord. This is why they
struggled for so long. It needs to be wet and able to slip into position. They installed it dry
with the sealant already on the glass. Both bad techniques.
Your duster has an easier shaped glass to install than the mustang shown in the videos
due to the rounded corners.
Their is no need for all the struggling and mess the fellows put themselves through.