A few years ago I completely stripped a '77 Westy to do a color change paint job. Before putting the interior back in, I filled the ribs with that expandable foam in a can. I then sprayed everything that would be out of sight with 3M rubberized undercoating. I also carpeted the area underneath the rear seat/bed. All this resulted in a VERY quiet Westy-almost too quiet! I could barely hear the engine, which I found I didn't like too much-but I could carry on a conversation with someone sitting in the back without yelling.     Jeff