I wound up ordering the 16:1 box so I hope there's no problems like that with it! Living in Canada the aftermarket people don't seem to get it that when they say " just send it back to us and we'll fix it" it's a LOT of hassles and expense to do that, especially to the US. That's why more and more guys are keeping orders above the border. I have Doug's headers on mine and it looks like enough clearance around the stock box, so hopefully no problems!