2 seperate +12v rails into 1 Graphics Card?

I have an Antec Truepower New 750w. It has 4x +12v rails each at 25A. The non modular cables contain 2x pci-e 6+2 connectors each on a different rail at 25A each.

My question is can I plug a pci-e connector on +12v coming from rail 3 into one socket of my soon to have GTX670 and the other +12v coming from rail 4 into the other socket of my GTX670. Is this necessary or am I just paranoid that I do not have enough power to run a GTX670 on a single 25A rail.

Thanks