I am 6’ tall and looking for a large capacity 65 L+ size backpack for backcountry overnighters. I have a 24” torso. I can only seem to find up to 21” torso women’s packs at rei.com. What pack do you recommend? Can I use a men’s pack or are they designed differently?
We'll make some pack recommendations here, but to answer your question first: yes, men's and women's packs are designed differently in a couple of areas, namely, the hip belt and shoulder straps. The hip belts and shoulder straps on a women's-specific backpack will be shaped to conform to a woman's body. That doesn't mean you can't comfortably fit or use a men's backpack, it is just something you'll want to keep in mind. Additionally, you may be able to swap out a women's shoulder harness and hip belt for a men's in order to truly dial in the fit.
All of that is to say, there are many options for making sure you get the best fit possible for your backpack. Your best course of action would be to go in to your local REI store where you can speak with a pack fit expert and try on your different choices. Another option would be to sign up for a free virtual outfitting appointment with a backpack expert who can talk through your backpack fit.
In the meantime, feel free to check out these backpacks that have some of the longer torso lengths in REI's inventory: