If you've been riding a 170, a 175 will be a noticeable improvement given your height. A typical track frame will have a 50-60mm BB drop, so with 175s you will have similar or perhaps even more clearance than before. Keep in mind that a higher BB is really only for clearance, and not for speed. I went the other way and got rid of my track geo bike to get a relaxed geo bike for commuting.