Upgrading 3070 Ti to 4070 Super. Cables and rails?

My 3070 Ti recently decided to fry itself. I've had it for about 2.5 years. Instead of buying a new one I'm thinking of going up to a 4070 Super, mainly for the extra VRAM.

Only issue is I've been told that I'd need new cables and rails to have fitted. Cables I'm guessing are the PCIe cables, currently I have 6+2 PCIe cables though I don't know what I'm supposed to change them to. Rails, I have no idea. This is the first I've heard of them.

My technical knowledge only goes about as far as knowing what most parts are and what to look for in new ones. Any clarification on what I should be looking for? Using an Asus B550 chipset motherboard and a Corsair 750W TXM 80 Plus Gold PSU.