Truck Weighed with Lance 830 (Conclusion Pics)

I will be a slight counter arguement. I was close to the same rear weight as you and went with 285/70/17 tires at 32.7" with a 3750lbs rating, giving me 7500lbs total. That might be too close for margins for you but just giving an option. Not sure the height of your current 18" tires but I bet they'd be close. Just a thought. I have also thought long and hard about 19.5" tires too...