I agree that the rear bolted-on crossmember needs to be there, but I t does not need to be attached to any part of a transmission which does not have a torque tube.
It is my opinion that the original wimpy mount bracket which was attached to the torque ball collar was there simply to stabilize the torque ball from undue vibration, extending the life of the cork gasket inside. This mount just was not sturdy enough to support any transmission weight. In fact, when the tiny rubber pad rots away, the two metal parts of the mount remain separated.
Carl
