Jeff you will have to ask him about that. I found that one of the guys from the 67-72 forum had done it on his truck. He said it wasn't easy, but was well worth the effort. I told Roger about it, and he said he would give it a shot. I haven't seen the truck yet, but he says it worked great. He put it inside the door "and under the door panel.
Here is a link to a thread that I posted in a while back. Look down the page to my post and it has more links in it. These might provide more info for your how to page...
Sound deadner