Rubber Floors

You used to be able to buy the flooring materials, (carpeting or rubber insulated matting), for these trucks at the dealership parts departments, they came with the insulating material already laminated to the back side, just exactly like the originals, I can't remember pricing details though. You have to remove the seats, shifter boot, and door flange plates in order to install them, but they do seem to bring the truck interior back to life sometimes.

 

Suggestion;
Google rubber floor mats, or maybe floor covering. I got mine from Northern Tool, the diamond tread pattern which is available in a couple of color choices. This stuff is not actually rubber, but a poly-something or other. (same stuff as the Huskyliner brand floor mats, very durable, easier to clean than the factory mat). 7 & 1/2' x 12' (IIRC) roll of the stuff was like $300. KW wanted right at $1000 for rubber mat and insulation for JUST the cab floor of my W900 couple of years ago. After stripping and cleaning my floor, I painted it with the rubberized "Cool Seal" paint that is designed to coat and insulate mobile home roofs, then added the foil backed insulation stuff similar to Dynamat (this stuff, along with the slightly more expensive Dynamat is available online through an auto body supply named Eastwood).
There is a local rubber and gasket supply near me that sells several products that can be used for an underlayment. They also offer similar to the factory mat. Maybe there is a store close to you that has something like that.

Another thing;
Don't throw your old mats away too quick! You'll want to use them for a pattern.

 

DB Engineering makes a product that has the mat bonded to the insulation

 

Dose guys got their act together! With the mat and insulation bonded together, install should be a snap.