The Asus website(http://www.asus.com/ca-en/Graphics_Cards/STRIXGTX970DC2OC4GD5/specifications/) lists the card as being 11 inches and Cooler Master(http://www.coolermaster.com/case/mid-tower/elite-430-black/ <-check under specs) lists 12.4 inches as the max for the case.
It should fit fine.