Crank legnth is determined by your cadence style, not by your height unless you are way off the scale/tall or short, which you are not.
In general, the more you spin, the shorter the crank legnth. Track racers usually use 165mm cranks because they tend to spin at very high rpms, 140+ for most sprinters. If you mash, then longer cranks give you a better mechanical advantage.
So figure out whether you mash or spin and get cranks accordingly, but 172.5 is really a crank size that is near the middle of what most people use, just a little weighted towards mashers, you might want to just consider keeping them. If you move radically, say 5-10mm, it will affect your spin and you'll have to get used to the new pedalling style.
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Il faut de l'audace, encore de l'audace, toujours de l'audace
1980 3Rensho-- 1975 Raleigh Sprite 3spd
1990s Raleigh M20 MTB--2007 Windsor Hour (track)
1988 Ducati 750 F1