OMG....you said something nearly positive about IA. Gotta get a cup of Joe to celebrate.
140 lbs........The truck thinks it has a Jr High kid in back. No, that is a token weight. Makes you feel good, but not very effective. I don't have one in this truck, but in the past I used the ShurTrax water bladder in my GMC 2500HD. IIRC, the smaller ShurTrax bladder will place about 3-400 lbs in the bed.
Its a pretty slick system. Late fall fill with water using a garden hose. It is tied down in the bed during fill. It will freeze into a block of ice without splitting the bladder. In the Spring, remove the fill cap, it will drain as it thaws. It is only about 2 inches thick and will handle loads on top, especially when frozen. There were loads which caused me concern on tearing, but a simple 3/8" sheet of plywood solved the concern.
Side benefits, it doesn't slide around in the bed, just folds up to store, empty weight is maybe 5 lbs, no sandy mess in the bed,
I need to get one for the truck before winter of 2023 arrives.