I have the same size tires on my 51. Mine are LT's and I've had 1200 lbs on with no problem. I wonder if yours are passenger tires and underinflated for their max load, causing the sidewall to bulge. Also, unless you scaled those loads, theres no way to know how much was on there. The payload is your GVW minus the empty weight of the truck. My 3104 weighs about 3700 with me, the spare and a few tools. I think GM weighed a truck with a 3 speed, no fluids, spare, jack or any flies on it to come up with 1500 lbs. My 2 cents worth, I love my truck and Chevy in general. After having Fords for years, when I bought my first Chevy a glowing light came from above and I'd been saved! John
