I am not sure on that one, I would recommend going through Bell and getting a set that he has re done. These thing really hold up well, you cant beat them for the cost, and yes they are stronger than stock. Some where on here there is a write up on axle stregth. I believe they break some where around 5000 lbs of torque. I would have to look into it. It's a really nice way to go for the money.
