You cannot brace a differential as ford has done and have a 400HP with similar torque motor to it and not have the thing bend bolts or snap bolts.
This is why the bolt is breaking...
In this video is a Pontiac Solstice. It is the first year they were released. The following year the problem was corrected. At the 2:00 mark in the video you are going to see the nose of the differential pitch upwards. This is what a differential wants to do when accelerating. That is because of the torsional forces being applied to the ground. Those same forces are what cause the nose of a drag car to lift off the ground, it is the nose of the differential that is going the lifting.
GM also ha a bad way of attaching the diff on a vehicle that had only 170HP/TQ and the car only weighs 2900lbs so easier to move.
See how the nose of the diff is bouncing up and down. This driver was only driving the car and it was not gunning it off the line which is when the problem is the worst. Even when there are the 2 bolts in place the bolts may not break but there is still the pitching that is occurring and this is going to trash the input shaft bearings on the diff and I would be suprised if the bolts didn't bend.
How GM corrected the problem for the Solstice is the ONLY proper way to correct the problem and that is to install a torque bar that bolts onto the nose of the differential and heads down the propeller shaft tunnel and then bolts to the tail of the transmission. Leverage is what gets used to hold the nose of the differential in proper alignment with the transmission and stops that rotation of the differential.
Trying to fix this issue in any other manner is going to require the use of rubber mounts and the differential is still going to move around and put stresses on those mounts. There also has to b structure under the vehicle that is able to hold the diff and I don't think there is anything that can be easily bolted to that would solve the issue.