thermal sensor question, 2 tb hard drive swap

Speaking of the thermal sensor, I just bought 2 2tb internal HDD (Hitachi Deskstar 3.5 and a seagate barracuda green) and both of them have different thermal sensors. Baraccuda is 4 pin, and Hitachi is 2 pin. the pics of the stock western dig looks like it has 6 pins, from a video I saw online of this. I want to trade out my hard rive myself, but I don't want to @!!@ it up, so any suggestions or comments would be greatly appriciated ( I have a 2007 27in 2.66 i5)