output and half shafts treated to strengthen them. Years ago when drag racing was more common/in vogue, it was suggested by Mike Kojima that those who drag race have their output rear end components aircraft quality shot peened and cryotreated. His recommendation came after a number of us drag racers were experiencing output shafts that failed (twisted). If you are running an NA differential, all the more important to get those parts treated. If your axles are bouncing/hopping during the burn out and/or launch you might want to give SpecialtyZ a call and get a set of their subframe spacers (to eliminate or reduce axle hop). Hope that helps.
