i want to run a gtx 670 superclocked but im not sure if it will work in my motherboard also i have a 6950 at the moment and the motherboard is a ASUS m5a 78l-musb3 MOTHERBOARD.
Yes, it will work but, as stated above you need to check that your power supply is good enough. 500W minimum according to Nvidia's website, but I would aim a bit higher than that personally.