Most cards WILL fit in most cases. But if you are in doubt you can go to the manufaturers and see if they got any size you would like. But most of the time the graphics cards will be the same size independent on the manufacturer. If I was you I would first check the space you got between other hardwares. There should be at LEAST, 5 cm of distance between other hardwares to evade overheating. If the graphics card is too big buy a new case. They are really cheap, plus you will be able to see if all the hardwares are in good condition when changing cases.
Hope this helped, Erik Jansson