On my 46 I cheaped out a bit and used the Summit Racing version a few years ago. It was worth the effort.
https://www.summitracing.com/parts/sum-879024They have a 5 or 9 sheet packs available, sticks well- no smell. Made a significant difference on my 46, did firewall, floors under the stock rubber mat, behind door panels, lower rear wall of cab…did not do roof as didn’t want to take on R&R of a now perfect headliner. I closed all non used holes in firewall with washer/ bolts before installing.
Used a deep socket as a roller to smooth it out which really helped. Surprising how solid the doors sound with just the back side of door panels done(didn’t want anything on door exterior or bottom for potential moisture issues)..
What truck are you working on?
Chuck
