Most of the old 737-300's in the UK now have a min GR Up speed of 170. (Flap 10) It used to be 160 but the scare about rudder hard-overs changed that. I've flown these aircraft for two UK operators and both were the same. The next stage of flap (15) has a min speed of 150 but requires GrDn to avoid loud horns!! 767 and 757 use variable flap speeds with weight so at lighter weights can actually fly slower than the 737. Some operators of the NG 737's (700/800) use variable flap speeds from the Speed tape indicator so at light weights can meet your requirements with gear up.