Quick question, GPU (GTX 295) block orientation?

[Swiftlegend]

I recently fitted my GTX 295 with the EK full body block, the instructions say one of the top two inlets should be in and one of the bottom two inlets should be out, I have looked around and many say only CPU blocks have flow orientation. Would I be alright going upwards rather than downwards do you think? I have seen a few builds that have done this but I dunno if it will damage my block.

Thanks