Sub-frame connectors

I weld them on the Torsion bar crossmember and then jack them up against the pan where it starts to lift my car off the stands. Takes that sag out of the car. Funny the doors closed better. I test the door open/close as I do it. Why would you want to lock in non engineered sag?
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That's pretty much how I installed mine aswell.
Drove the car on my 4-post lift, positioned the connectors under the car, welded the front to the crossmember with a few welds. Then put a transmission jack under the rear of the connectors and pushed them up very tight against the floorboards and over the rear framerails and welded them in.

Doors opened a little different but I find it more assuring some of the body-sag has been taken out of the car now.
Doors hinges are mounted with bolts so you can adjust them. That why they are there for.