There should be a tag in your door frame or in glovebox, stating the GVW of your truck. Go to gravel pit with truck and half tank of gas in it, get weighed empty. Subtract your weight from GVW on truck plate, you have best SAFE load for truck. Many times it can haul more, but SAFE limit for brakes and suspension is manufacturer's statement. My older 2-ton was a 16,000 GVW, but some later years they upped that with stronger frames, springs and axles. I always figure about ton for 1000 lbs of load, so around 4 yards is probly close. Check to see what your dump frame has on it for an ID plate too. It will give capacity or at least volume of the bed. If small wheelbase, probly not over 5yards, but may be as small as 3 yard dump.
