I just talked someone else through this. The torsion bars are incrementaly indexed from one end to the other for very fine adjustments. As Doug said you do the same as any build where you use a strut rod in place of the shock to get adjustment correct. That is way too low obviously and it sounds like it might be one spline out at one end. Does your
oil pan hang below the frame rails? Shoot me an e-mail address if you need the manual.