Lol... you don't need any of that. The Cable will be directly compatible with the socket and will leave 2 Pins unconnected without any problems. The only thing should be that the 2 Extra Pin should not be blocked by any component on the GPU or Mobo.
@brythespy: What DATA are you talking about? Those are Power Connectors.
i was thinking the same thing about what brythespy said, but sorta new to all this stuff still so i didnt want to say anything incase i was wrong then id look like an idiot XD
in my case the 6pin socket blocks the 8pin connector, so the 8pin wont go into the socket. i could get an adapter, but if i were to find a way to cut the extra 2pins off safely, it WOULD work, am i wrong? because a 6+2pin is the same thing as an 8 pin, just already broken off professionally right? XD