Use the 2700k ones for flowering, and the 5500k ones for vegging I say. I think your numbers are mixed though... Typically, soft white bulbs have a lower K value than daylight bulbs.
But here, read this:
Lumens are a quantitative measure of how bright a lightbulb is. It's a measure of "brightness" so to speak.
The "k" value is called the bulb's "Kelvin" value. This is a measure of the "colour" of the bulb. The higher the "K" value, the bluer the light is. A 6500k bulb will have more of a bluish spectrum than any bulb with a lower kelvin value, and less blue than a bulb with a higher value.