When I started reading your post, it scared the heck out of me. What you are calling jacks are jack stands.
Your post made it sound like you were under the vehicle supported only by two hydraulic jacks.
As far as your Durango, more than half of that 6700 is on the front wheels. That is getting very close to the rated capacity of the 2 ton stands, I like to have plenty of reserve capacity.
I threw out my old steel ramps years ago, they creaked and groaned. I now use plastic honeycomb
Rhino Ramps, much safer. When I use the stands I always back them up with something.
I’m the wrong side of 80 but I still enjoy working on a car.I just try to make sure I have everything I might need in reach before I start because getting from standing to under the car and back up is frequently the hardest part of the job.
When I do my once yearly oil change now, I do it when the engine is hot. I pull the car up on the ramps and pull the drain plug, remove the filter housing, change the cartridge and let the oil drain overnight.
Although my Camry has a claimed capacity of 4.7 quarts, it take 5 qts to fill it when I do that. I wish Toyota used cross hatching on the dip stick, the oil stays so clean it is hard to read on my 8+ year old car even after 6 months.
I was thinking of getting a new one, but after reading the problems with direct injection engines I think I will just keep driving this one. so far the only thing other than wear items and oil changes, the only thing I have done is replace a w.washer pump. I watched a youtube video first to see if there were any surprises and the idiots who made it wanted me to replace the bumper cover,ridiculous!