Torsion Bar Crossmember Replacement

Picked up a '72 Swinger recently. It has the usual rust issues (Quarters, Fender Extentions, Front Floors). The BIG issue, and the one I am going to tackle first, is replacing the torsion bar cross member. The original has a golfball sized hole rusted clear through it just inboard of the passenger side torsion bar socket, right about where the Tranny x-member is!!!! Luckily the car came with a replacement from a parts car.

My big question is how to jack up the car to perform the removal/replacement? I know I want to level the chassis but how do I support it?
Do I jack it up from the front and rear subframes?
Do I jack it up under the diff in back and put the front on ramps?
Should I remove the engine and as much weight as possible to unload any stress in the chassis or do I want it stressed.
I'm not worried about the cutting/welding end of the job, just not sure how I should support the car while I am operating on it.

Thanks
Author: admin