Without question 176. I had the 171s last season (I'm 5'8") and they were just too short, I'm getting 181s this season. There's a lot of rocker on the FR, which is one of the reasons it's so fun, but it also makes it ski very short so you really need the extra length. The way I look at sizing for the FR, whatever size you think is best for your height/skier type, go up one size.