Re-indexing only helps if you run out of adjusting room.
The problem with the lifting the front end (cranking your torsion bar) is the angle of the A-arm. When the angle is increased there is less torque on the torsion bars. In an extreme example, if the A-arms were verticle, the force would be verticle, there would be no torque on the torsion bars. In the other extreme, if the A-arms are horizontal, the maximum torque is applied to the torsion bars. Of course I'm talking about "static" loads here (perfect pavement or at rest).
With dynamic loads, such as driving on typical Memphis streets
is another matter. The higher your A-arm angle, the more the shock is transferred through the A-arm to the joint, which doesn't have any "give" and less is transferred to the torsion bar to cause it to deflect (actuate your suspension). Which is why a torsion crank makes the ride ruffer. The repleacement A-arms and torsion bars with more constant spring rates help this significantly.
I hope this helps, if I was at work I would make a little AutoCAD drawing for a visual aid.