Alright, I got some quick "after" pictures the other day before I put my floormat in. No more rust in the floor, kick panels, or the front corners of the cab. Mission accomplished. Plus, I didn't have to pull the rockers off, icing on the cake.
As you can see, I put FatMat down and tried to cover the flat portions of sheet metal, as well as some other areas. I've never really messed with this stuff before, and I didn't find it very enjoyable. But, I do want the cab to be as quiet as possible, so I felt it was necessary. My only word of caution is that when you get ready to stick this stuff, BE READY, because it really sticks. I'm not very impressed with the quality of the job I did, but it ought to get the job done and it's under the floormat anyway. I will do one nicer than this one day.
I decided to go with the vacuum molded vinyl from LMC, which comes with the insulation pad you see in the pictures. No pictures of that just yet, I'm still trying to get it to smooth out. What a PAIN this thing was. It requires a fair amount of trimming and because of the way they package it for shipping, it arrives with some serious creases that make it tough to fit it to the floorboard, much less get it to lay flat. My best advice, go to member Bruce88's "
It's Just A Pickup" thread and start at post #556. He did an excellent job of explaining how to install one of these.
I also put in a new firewall insulation pad assembly from GMC Paul's while I was under there. The original had been soaked in brake fluid from a leaking master cylinder. This thing would have been much easier to install with the stuff behind the dash removed, but I managed to get it in there.