Torsion Bar Ride Height Adjuster troubles

Whoop, there it is!
I see the problem clearly now. Man that is ugly.
With the front fully assembled there is a turning force up there, which is pulling the back end up into the floorboards. my guess is the LCA bushings or their pin-tubes are also really tired. I highly recommend to remove everything from the LCA, and let it rotate to the floor.Before welding the back up, I would inspect the pin-tube and replace the LCA bushing.
But firstly I would inspect the entire front frame support system, from the floorpan to the firewall to the fender aprons and the entire length of the stub frame. If the stub frame is not well supported, the entire K member may be twisted up.
From the last pic, it is clear to see the floorpan is toast. It is easy to imagine that the stub is compromised.The floor and apron are the stubs main supportworks.
The weight of the engine and tranny may also be playing a role in pushing everything out of alignment, by twisting the K-member and drooping the tranny x-member. I hate to say it, but it might be best to pull those out too, and get the body supported, somewhere other than the anything attached directly to the frame., allowing the frame to relax.

Before you go thinking;"that's insane", you need to know that if the frame moves while driving,then the alignment goes away and the car becomes self-steering. I once ran off the road as i was crossing some diagonal train-tracks, at about 50mph. This was directly traced to unsupported frame stubs .74Duster.