WaGriz is a very, very tough place to win. App will have their work cut out for them and I wouldn't be surprised at all if Montana comes out on top.
However, leading up to last year's game, I remember hearing that there was no way the App State OL and DL could hold up for a full game against Montana. The Griz had just as much of a size advantage up front in 2012 and App was able to hold their own. The front seven gives up some size but they are very athletic.
I'd be surprised if we did not see another tight game. Anyone expecting to see Montana steamroll App will probably be disappointed.