I am also interested. I had a set installed 15 years ago on mine when they did the IFS front end. Since I recently dragged it out of storage, I noticed with just 4 fenders and a few boxes of parts, the rear leafs are flat and bottoming out. Truck has sat unloaded for 15 years, so I cant say it was due to over loading them.
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IMG_3702 by
Andrew Bushnell, on Flickr[/IMG]