From a lifetime (30yrs)of hunting & shooting sports, the associated muzzle blasts & gunfire has rather messed up my ears to the point that most engine noise bugs the crap out of me, even though the Duramax is the quietest diesel made!!!
Does anybody know of a DIY kit that can be added to the firewall & hood to deaden some of the sound?
Or some type of spray-on DIY product?
Or anything?

You can try Dyna-mat. Dynamat.com or..I used to spray in-bedliners and we did spray the entire truck floor, firewall, fenders and underside of the hood, but the truck gained quiet a bit more weight. (Dodge diesel) We had to take the truck apart to get in and spray..$$$$. I also used 1" foam that had a foil on one side that I glued to the firewall inside and out, underhood and any place else i could glue it too, but never saw the truck again, so i don't know if that worked, another Dodge diesel. All seemed happy when they left the shop..

Was the foam mentioned rigid or flexible?
What type of glue was used?

dlshunter
The customer suppled the foam. It was a rigid black foam with foil on one side. It may have been from the building trades. He was a contractor. I am an upholsterer so I used neoprene contact cement used for the auto/marine upholstery trade. Good luck

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