The statement that no matter what you run for axles sooner or later you will break them is not true. I've done this for over 35 years and have broken only two axles. Both of those axles were replaced with stronger axles and that ended my problems with axles.
I have on the other hand broken a full half dozen drive shafts, a few springs and shackles, and shock mounts and shocks.

 

Yeah, it will hold up. Ive got 49's on a dana 30( I didnt build it and im swapping to a dana 60 in a few weeks). But then again I don't run a dont driveshaft beacuse of mis-matched gears. Hell- I've seen a guy with 54's on toyota axles It will hold up, but your gonna break stuff. Balljoints will wear faster, u joints and shafts will snap too. If you're prepared to constantly replace stuff, then go for it-it's your rig. If you don't wanna have to worry about it, then step up to beefier axles.
Either way, run the right gears.