I am planning on going to the Bighorn mountains in January. My spare sled is a '00 mountain max 700 141 which I would like my girlfriend to ride. We live in North Dakota and pretty much just trail ride in low elevation areas (under 3000 ft). What do I need to all do to the sled in order to ride it in higher elevation ( 6000 - 8000 ft)? The only mod to the sled is an aftermarket silencer which was already on it when I purchased it. Thanks.