Nice! What did you use for sound deadening material? When doing my truck I used a product called "Lizard Skin" for sound deadening and heat reduction and overall I've been happy with it but I often wonder how much better something like Dynamat would have been.
I intend to use something like Lizard Skin on the 69 K5 underbody to block heat and sound, since we plan to bedliner the interior. On the 78 I went the cheap route to experiment, I used peel and seal to mass dampen the flat panels, approximately 30% coverage, then layered that with some 1/8" foam duct insulation to insulate against heat and higher pitched noises with almost 100% coverage. Then of course the new carpet padding and vinyl floor on top of that.
I know, I had heard all of the negative reviews of using peel and seal, such as falling during the summer heat and the asphalt smell...but I left the rolls sitting in the floorboard of my daily beater for a couple days at 100* outside temps, the smell was noticeable, but not overpowering. Once installed in the truck, there was no smell at all on a few 90* days, I believe the 100% coverage by the insulation and vinyl floor seals off any scent. If you stick your nose right above the window channel when the window is down you can get a slight whiff, but that's it. As far as the adhesive failing, I limited it's use on vertical surfaces to the doors and rear wall, and there I covered the perimeter of it with tape to give it a little help staying attached.
It made a very noticeable difference in sound and heat, for the money I have into it I am very happy. It is easier to hold a conversation while driving, and the normal radio volume setting I use while driving dropped from 20 down to about 13-14, so I don't have to have the music cranked to hear it.