the cts stage 1 box as far as i know has the uprated ib5 bearings and ford viscous lcd, the stage 2 box then has the uprated ib5 bearings but a quaife atb diff then the stage 2+ has the uprated ib5 bearings, quaife atb diff and shot peened gear set.

as above its all down to how you treat the car, if you like hard launches off the line and dont smoothly change gear then your going to break it quicker, they all have there limit regardless of driving style though. id say a stage 1 thats treated right will cope with 200bhp, stage 2 around 240bhp and the stage 2+ around 280bhp but theres torque to take into account aswell as other things, the bc box i feel is the wear link when your running massive power though.

there are people on here who have their boxes rebuilt once a year just for piece of mind.

dave.