THE weakness of the 8.75 is the case itself and the pinion stem. The torque flexes the case and lets the pinion move away from the ring gear, which shells gears. When you get that crap going on, it pushes the cap off, as the mashed teeth are trying to roll over themselves. The billet cap will maybe keep it from breaking the cap, but does NOTHING to address what caused the failure in the first place, which is case and pinion stem flex.

This is where guys say that the 8.75 pinion stem is about the same as DANA, which is true...........BUT, the DANA housing is massive AROUND the pinion, which helps support it and the case doesn't flex. You can't do that around the pinion in an 8.75, because it's a drop out . You CAN make it out of a little better metal, but you can't increase the support area. So the drop out is better, but not FIXED