One time conversion tool I have used only does freestyle for 50 yard/meter distances. For other strokes like breaststroke the turns are a very significant part and I'm wondering how close a simple 1.1 conversion is.
Based on the 50 BR event rankings, I went from 58/90 SCM (38.54) to 50/141 SCY (32.61), so I definitely went faster but it's hard to pin down how much.
I think a large part of this was from changes in my weightlifting routine.