Are you going to throw any audio equipment in there? What did you do to get rid of all the rust (sanding, chemicals, etc...)?
I like those "old" 'Burbans. Can't wait to see how well the AT works and what else you do to the vehicle.
Since most of it was surface rust I just sanded, wire-brushed and used an oil based rustoleum primer and paint. It set up as hard as a ministers peter.
Its just a winter beater and summer family truck so the audioz will be small but it will have a flipout and a sub or two.
Deadener does help with road noise but is not the solution to the problem. I always suggest to customers that the deadener there floor and doors with a deadener like AT, then apply MLV on there floor and doors if possible.