Removed the entire interior of my 1988 379 except for the dash. Applied Hushmat sound deadener to every exposed metal surface including door panels. Then applied dynaliner 1/4" foam to the back of all the upholstery before reinstalling. Also put Dynaliner on the back of the new carpet. Drove it for the first time this afternoon. I wasn't pulling a load but the difference was nothing short of amazing. It wasn't cheap but worth very penny. Used to have to turn the radio down whenever I stopped at a light, but now I can still hear the radio at 55 with turning it up at all. My truck was so loud that I was exhausted at the end of the day just from the constant noise, because I do so much stop and go, up and down the RPM range. My son drives a new T800 and it is easily as quiet as his new truck. Also, took out the overhead console because the fabric had shrunk and was tearing away. Had it covered in a walnut veneer with a high gloss lacquer top coat. It looks fantastic. Way cheaper than a new truck but it's new to me again now.