I think they will be allright if u buy a good set from a good company, sierra gear i think has good ones.
I saw a 4 runner ifs one and it had 40's and 5.71's and they worked out allright.
I think it all depends on what brand u get and how well they are set up.
everyone around here runs 5.29s and they seem too break them alot i had a friend set them up that does a good job we set them up tight and they have held up too alot of abuse, 38's doing countless burnouts and dumpin the clutch all the time and never broke yet.
if u want just run 5.29s and a duel crawler and it should be fine and stronger too.