It reminds me of the time I speced a GMC chassis cab for a flat bed with a tommy lift. Rear springs were rated at 10,000 pound, truck weighed 8200 pounds with out a load. Load was typically 600 to 1500
pounds. I was literally wearing out rear shocks every 3,000 miles. To make a long story short I had to pay to have 11,000 pound springs put on, GM insisted it was an upgrade! Even though I had the track weighed and demonstrated it was impossible to to load more than 1800 pounds of appliances in the bed I was still charged. So much for GM specs.