I remember about 30 years ago, a customer came into our Service Station for gas, he had a 10 1/2 foot Self-contained Vacationeer camper sitting on top of a raised shortbed stepside Chevrolet K10 4 wheel drive truck, It sat perfectly level, I asked him how does his truck hold it so well? He told me he had spring work done at a spring shop that I have brought 3 vehicles to for spring work. I still couldn't believe it!