NVIDIA GeForce GTX 470 Voltage Modifications
yantronic over at VR-Zone has published a voltage modification article that is worth taking a look at if you want to volt mod a GeForce GTX 470 graphics card.
NVIDIA GeForce GTX 470 GPU Core Voltage Modifications
NVIDIA GeForce GTX 470 PLL Voltage Modifications
NVIDIA GeForce GTX 470 gDDR5 Memory Voltage Modifications