paralleling power supplies
after doing some research the gtx 960    "GeForce GTX 960 4GB SSC CARD" to be exact requires 400+ watts of power.

from what i see the power connectors are all on the 12 volt rail and i was wondering if i could splice the 12 volt wires from multiple power supplies to 1 connector so i could get the power needed or do i have to upgrade to a bigger power supply?

i do see you can use a separate power supply to power a graphics card so i would not have to replace the power supply.
No, you misunderstood that. It requires a power supply with 400+ watts of power. The card itself draws about 120w.
you mean that the minimum total suggested is 400?

and i was reading from the specs page

requirements section

however can i splice the power rails to spread the load across multiple power supplies?
You could, theoretically, but then it does not make any sense with the GTX960. Plus you shouldn't connect several 12V-rails from different PSUs together. Never. Promise.
what's bad about connecting multiple power supplies together? unless a lower wattage psu may feed off one of the higher wattage ones and bog it down or if one is faulty take down the others?
You're obviously ignoring the rules of electricity and I don't have time to explain the basics in electronic to you. Let's just say it's not that simple, you can do a lot of damage and in the end it's even hazadorus. What you want to construct is a redundant PSU, but that's not how it's done. If you use two different PSUs, plug one to GPU1 and the other one to GPU2. But avoid mixing up different current circuits.
#7 is what i was talking about externally powering the graphics card.

i do know about seriesing and paralleling i have done it to build a battery for an electric bike running on 48 volts 20 amp
Dude, please, I now don't even know what your problem is about. That guy in the video powers one GPU with an extra power supply, just as I mentioned above it's possible. It's still a big "be careful!" and a stronger power supply is still more than recommended
A battery btw. is electrically completely different to a PSU. Each battery has a closed curcuit and no shared negative pole.

Just read this FAQ if you're still thinking about it:
 I have done it to build a power wheels battery that is powered with 24 volts and it's running perfectly