Hi there again,

The Club 3D R9 280 royalKing is 268x122x36mm, you can find this information in our product page under specifications.
I don’t know the brand of your case but if it fits a Full ATX motherboard and you can see there is space in between the mainboard PCI-E 16x slot to your HD bays etc then it should fit.
Take a measurement tape can measure 268mm from the back of the chassis to the front.
Cheers