I recently did mine. The battery box is another story to deal with but you should be able to bend some sheet metal and rivet a box together to mount. Many people who have done the hollow mod have recommended using the K&N RU1780. Its big and red and looks tough, I hated it and it didn't work for me. No matter what air filter you use, the shock is simply too close to the carb to have anything fit, ergo don't throw away the rubber diversion tube when you remove the stock airbox. The problem with the k&n was that when attached to the tube, it was too heavy where it slipped on to the carb and would fall out on me when I rode. I didn't want to rig up some zip tie solution. Its also big and tended to hit my leg where it protruded from the frame. I cant remember what I have on now but I simply went to the local moto shop and ordered the smallest 'mushroom' type filter I could get that would fit on the rubber tube, and I spent $12 compared to the $45 I originally spent on the k&n.