67 Dart Build Triangulated 4 link & Mini Tub

On mine the lower bars are not off center to my knowledge. My brackets on the housing are all in the same spots. At least they measure that way. Your upper brackets on the housing may be causing the pinion to move if they are set too far forward or too far back the pinion angle will move.

I used 130lb springs in the rear and I just have them sitting in there not tightened up with a load on them, 250 will probably be too much spring in my opinion.