Will the antec bp550 550w power be sufficient for a gtx670?

yes. It will be more than enough.

http://www.nvidia.in/object/geforce-gtx-670-in.html#pdp...
it says it needs 2 6pin connectors

It does require 2x 6+2 connectors. Keep in mind though that it is a basic power supply through ANTEC which is probably mainly set to power a low to mid level system its not mean't to do anything intense. There is more to a power supply then the wattage the amps as well.

Will it work yes it will work you will have to use adapters to get the job done which the card will provide molex to pci-e power connections. However in the future you may want to replace that power supply with something little bit more reliable towards your current needs.

Like these
650W : comes with 2x 6+2 and has a high 12 volt amp as well as its seasonic based.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Another 650W with 4x 6+2 connections
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Don't be like the tards on this site take care of your computer and not go cheap on your power supply.