oldbluetruck, I have insulated the roof of my 46. I first put a layer of peel-n-seal on the metal roof to cut down on the noise, then I got a water heater blanket, you know the ones that are foil on one side and ground up carpet on the other. I used 3m spray adhesive to glue it up to the roof. Shinney side towards the interior of the cab.
It's been that way for about 8 years now and works fine.
George
