Hi do you mean you are going to buy another 970 to do sli, or did you make a mistake in writing 970 again?
If you are going to do sli, just put your current 970 in the second pci e slot to see if it will fit. If you made a mistake and you meant to say another card, just check the length of that card and measure if it will fit in, without the sata being in the way, if you provide your specs and case, we may be able to check it for you.