I scrapped the RX-480 because i got a sweet sweet deal on two Fury X's for 500 bucks total. They said it could not be done. It was told that I could not get two Fury X cards inside of the Air 240. Those people who told me i could not are wrong I managed to with a bit of finagling.
In order to fit two Fury X's you need place the bottom Fury X's radiator in the front of the case. For the second you'll need to mount it in the top. There is a catch however. IT WILL NOT FIT. You will have to essentially force the radiator into place and make sure your ram is only in Dimm slot 1 and 3. 4 is going to be totally blocked by the radiator. Keep the top of the radiator where the hoses come from pointed towards your ram. Screw in the top two screws closest to the hoses. The back two will not be able to be screwed in. The radiator will slightly obstruct some of the holes the case uses to snap the sides on but don't worry it'll still fit. Cut a piece of the foam that you get in the Fury X case to size and place it on top of the bottom radiator so it pushes up against the top radiator relieving stress from the screws placing the top radiator in.
Update removed the rear fan next to the power supply and added a ax1500I. it fits well but has no space for extra fan.