Need advice on frame connectors

With mine (70 Duster); 2 jackstands under k-frame, each side; 2 at front pillar; 2 at front of rear spring area; 2 at rear bumper crossmember. Leveled it it both directions, and back halved, sub frame, cage, etc. Door gap never moved. We will see, when it hits the floor. A buddy found a book, for his 69 Charger- It shows where the factory supported the body, while installing everything. I was close to factory on the Duster, but think it will work.
Support the car at both sides at the k-frame, and the subframe, at the front of the rear spring hangers- level those 4 points; then jack and shim both ends.
Make marks on the floor, so you can square the rear. And don't make my mistake. For center points, use the center of the front ball joints, to the center of the rear spring eyes.
Now the front and mid is aligned; chalk line the floor from your now centered chassis, and use plumb bobs to keep the back half in line.