Changing the GPU Fan?

So I've been wondering if realistically replacing the the fans on a gpu will allow more headway for overclocking? I have a 7790 which I will have to stick to for a few months but I was wondering if say for example what would happen if I replaced it with a 7970 fan (the 3 fan solution). Is it possible and would it even help at all?

Extra info: I have a asus direct oc ii to be exact

this should be what your looking for and says it supports the 7790 card and keeps the card nice and cool got it for my friend to replace his 6870 stock cooler that sounded like a jet