how much light

ok this is my 1st cfl grow I am in my 2nd week flowering I have 3 2700k. The lumens are 800 a peice I just found some more that are 1600 a peice. Will there be a big difference if I switched the bulbs now

You should get a sizable difference. The extra lumens will def give you fatter buds and as its only two weeks into flower you should get nigh on maximum increase compared to old bulbs.