OK thanks! That is what I thought. Can't I also put it in the PCI x8 slot?
My wireless card is this: http://www.newegg.com/Product/Product.aspx?Item=N82E16833166076
EDIT: So rather than putting the Wireless card in a PCI slot that is too big, I can just move the GPU and put the adapter in its proper place? Seems like the best way to go.