I heard that you shouldn't sli two aftermarket gpu's because it'll blow air in each other, and blow hot air around which is bad. I saw the reference 970's with back plates which should solve the first problem, but reference cards don't oc as well as aftermarket gpus. Is it possible to install backplates yourself? And some people said my case case has many expandable fan slots. So would that solve the hot air being blown around issue?? HEEEELP (My specs are in my signature)