I was helping a friend move a weekend ago and it's the first time i've ever hauled anythign with my 4/6. He didn't have a bunch of stuff but he did have a weight bench and some weights about 350lbs worth. anyway i loaded those up and we drove back his new apt. That load didn't bring the back down but a couple inches. I mean over little bumps i could feel the axle hitting the bumpstop (or the tires hitting the fenderwell) but nothing major. After unloading it looks like the tires sidewalls may have rubbed a little on the fenderlip. Does that make my tires more vulnerable to a blowout? How bad is it?