Adjusting rear ride height on a 70 Charger.

[b5blue]

 I installed new Mopar HD leaf springs over 18 months ago and am thinking of ways to correct the side to side stagger at the rear of the car. With an extra spring on the passenger's side, that side sits a full 1 1/4 inch higher than the drivers side and that's not including my big butt in the drivers seat. I'm going to move the spare tire and jack to the high side of the trunk and thinking of using the front spring mounting brackets that will let me lower that side 1 inch. (They come with 2 sets of holes.) From there I could shim the axle at the spring mounts to tweak a bit closer.
I'm shooting for a level chassis @ factory specs. as the front end is totally rebuilt, ride height adjusted and aligned pretty close to ideal. I have new UCA's and off set bushings I'll install one inward one outward when I convert to 11 3/4 rotor disk brakes. That will let me correct the last bit of alignment my guys couldn't get and complete chassis-suspension adjustments and modification before adding sub frame connectors.
It occurred to me while doing body work on the car that if the rear isn't level when I adjusted front end ride height "side to side level", the load on the torsion bars would be unequal some what.
I know there are many discussions on rear height adjustment and was wondering what others did to raise or lower that might help me? 
Thanks, b5
       

[HPP]

 1 1/4 seems like a lot for only one additional half leaf. I'd make sure both leaf mount points are identical in height and location, shackels are the smae, etc.

You can offset the right rear height by cranking in some additional height in the left front torsion bar. This will raise that corner of the car and balance the appearance of the right rear corner.

[b5blue]

Thanks, yea seems too much...I want to avoid uneven loading on T bars.

[twodko]

I sure have no insight here but it would seem cranking on only one torsion bar would twist the entire body to some degree. 

[cdr]

jack up the rear of the car & put level stands under the frame just in front of the front leaf spring hanger,then level the front with the torsion bars,then remove jack stands & then remeasure all four corners & let us know how far off it is. this must be done on a level area.

[HPP]

I sure have no insight here but it would seem cranking on only one torsion bar would twist the entire body to some degree. 

Its already twisted, we are jsut equalizing the twist. Unless the uni-body is welded together on a surface plate to ensure its flat, square, and plumb, they all havesome amount of  twist built in to them from the factory. Add in factory tolerances that allow up to .25 variation in structal components, and it is entirely possible a car will have "wedge" built in to it, sometimes a substantial amount.

Adjusting the cross car suspension point for balance is not an unusual trick and has been done for decades. Ever watch a Nascar race where they talk about taking a round of wedge out of the rear and adding one to the front, they are adding twist to the chassis to equalize the force on the tires. We're doing the same thign by turning torsion bars up or down.

[Kern Dog]

I had a similar situation with my 70 Charger. The side to side difference wasn't as extreme as with your car though. I bought SS spring hangers and drilled new mounting holes. Since the right side was higher, I drilled the RH hanger 3/8" higher up. Afterwards, the car sat within 1/4" on all 4 corners. I'll bet that it is closer than they were when new...

[b5blue]

  Thanks I like the idea of raising one side and lowering the other. The car was a drag race only for 8 years before I bought it, a lot was messed up like the 8 3/4 truck axle, it had the mount pads welded out of alignment so the springs kinda splayed outward in the back. Weekly hard launches cracked the passengers side LCA in a weird pattern around the adjuster's flange also.  I fixed/replaced all that mess long ago but now all is fresh new parts front and back, adjusted and aligned.