I use point 1, but for point 3 I use the subframe behind point 3. I snapped a bolt at one of the diff bushings after lifting at point 3 for years. I don't lift under the diff anymore. Getting the broken bolt out of the diff was a major PITA and I don't want to do it again. I don't need a block at point 1 unless I'm trying to get extra height. Usually, I will raise the front as high as possible, set it on jack stands, raise the rear and put it on stands, then using a block of wood on the jack raise the front further and set it back on the stands higher, then do the same at the rear. Makes it much easier to work under the truck that way and makes using a creeper much easier.