[82 Silverado 4X]

Cadillac quiet is something that has always been something that our trucks never had.
Here's a few things I have done that has helped me in the past:

Replace the door and window weatherstripping with new but use a bead of black weather strip adhesive on the back side when installing it. This eliminates the air from getting around the backside of the weather strip.

I went to a junk yard and removed the faced type thick insulation from under the carpets of a late model luxury car. I cut out peices to fit the doors then used duct tape to install it before I put on my door panels. Most junk yards are happy to see you take it and usually will give it away free.