Agreed with others, if you need all 4 molex adapters for your PSU because it does not have any 6 or 8 pin pcie connectors then you need a new PSU.
Any PSU that does not have PCIE connectors was not made to support a graphics card like the 970.
FYI, just because they slapped a sticker on it that said 600w in absolutely no way means it was tested or required to output 600w (more likely it will fry itself trying to output 400)