If you shim the tacase down to make tha angles match, you'll have to drop it more than you did the axle, since the lever arm length is longer (length of trailing arm vs. distance from front motor mounts to tcase mount), and I think it would wipe out any gain you got with the rear lift by dropping the tcase into the path of the gnarlies...

The axle trailing arm mount is fairly thin metal and a die grinder should oval out the holes pretty easy and quick.

Not responsible for advice not taken...