I recently had a scare when my girl was in my Z71 and doing as I asked, power braking short bursts. I was under the rear axle area and was up on drive on ramps. Both the ramps shifted at same time and almost spit out the back and that would have brought the rear diff down on my waist. Was a little scary. She is now freaked whenever I crawl under the vehicles I work on. In you case, when you do this the engine will not be running. I now use two sets of ramps and elevate the whole vehicle and is then level. I have never been a fan of jack stands, even though I worked with them for over 40 years. IMO, drive yours up on 4 ramps and set the park brake. You can also do as I do. I have the rubber wedge wheel blocks. You can kick those in and set those while up on the ramps.