I dont think I altered the airbox at all. I believe all I did was match the mounting holes to the adaptor plate. Same with the filter cage, which was also the 500 cage. I agree, it was a pretty easy, straight forward build! Heres a tip for better routing of the clutch cable. I used a tubing bender and straightened out the curve some in the metal tube part of the cable. This allowed me to run the cable in front of the radiator, just like on the 250, and I used the 250 cable guide/loops also. This allows a more flowing routing of the cable and eliminates the sharp bend that it would make at the top of the radiator when routed behind the radiator. It also eased up on the clutch pull some. The cable can also be replaced with out removing the tank or shrouds. I also use a MSR clutch perch and lever with a second mounting hole for the cable. This is NOT the Raptor lever that MSR sells with 3 holes. The lever also has a bearing in it at the pivot point. My clutch pull is as easy and smooth as a 250.
