skanj0 - Thank you!! I don't know how I missed the lt295/65r20. I looked down a list of toyo mt's and looked for the highest rated tires and only saw the 18's. Now I just need to determine if my stock 20" wheels are rated in the same ballpark.
BCBigfoot106: I don't know what to tell you but that is what the scale said, and I seriously doubt there was a problem with the scale as it was an Oregon DOT scale. My freshwater was full and my fuel tank was probably at about 1/4. The truck is a diesel, but like you said, I don't think that adds too much weight to the rear axle. I did have a load of firewood in my rear basket carrier which probably weighed about 250 - 300lbs, but again, the weight was MUCH higher then I anticipated.