I smashed stock birfs on 35s for years and broke plenty of them , I also used to wheel hard and not give a crap about my rig , if I babied it I could keep the axles alive but usually ended up breaking them , went to chromos and 37s and never looked back , currently banging 40s on rcvs and they are holding up well but if you have duals or 4.7s in the case thatll play a big part whether or not you'll break or not , having control over the rig and not having to ride the clutch makes a big difference , that being said if you've never replaced a stock broken toy birf on the trail then lucky you haha