Time to resurrect this thread.
I'm about to jump the tank, as it were, with my IRS.
To recap, my rear differential is either missing (or it's severely damaged) clip on the side yoke (probably the left side).
My plan, today, is eliminate the driveshafts as the upper control arm. I plan on putting an upper rod from the top of the trailing arm to a pivot point above the differential.
At the same time, I'm rebuilding the bearings and replacing the front rubber with a johnny joint.
In my research, I'm going to put the upper mount perpendicular to the lower mount, the inside mount will be 16 1/2" from the outer mount. That should give me similar, but better camber.
Am I missing anything? (I hate pulling the car apart again, but it's frightening to drive, so, rather than wreck it, I'll "fix" it).