I used the same style here is what we did back when we installed them.
On the two post lift, We clamped the frame ties front and in place.
Then we lifted the the car under the rear of the frame ties in the rear, And under the torsion crossmember in the front . Once it was in the air and level, We lifted the center of the rear with a screw style jack stand and removed the rear shackles and left the rear on the jack. So now there was no weight hanging on the shackles or shocks.
At this point, We opted to weld them in due in the past others I bolted in didn't hold tight in the rear. You could see the shadow of movement around the side of the frame ties and the bolts.
We also installed the molded style in the new car. Stronger but more work.
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