Changing rear tires or not...

I really appreciate all the responses and info. The tires I have now are rated at 3197 each and my rear axel weight when I brought it to the Cat scales is about 6450. I feel I'm right at the max limit of these tires and I just don't like being right at the edge like that. The rear axel rating is 6400 if I remember correctly as well. I just don't feel comfortable riding that line for hundreds of miles in the summer with 100 deg weather. I think I'm going to go with new 18" rims rated at 3600 lbs each at 8.5 wide and some Michelin 275/70r18's with a 125r load index. 125 is still a 10 ply tire but has 3638 lb rating. That would give me about 7200 rating and a comfort zone. I installed air bags and at 17 lbs i'm dead level. I agree I'm not worried about this truck handling the weight and the limit is really stock tires and rims. Same axel as the 3500 just one more spring and heavier rims and tires. The really great thing about having the dually in my opinion is if you have a problem with a tire you still have three left to get someplace. Like having twin engines on an offshore boat. One 300hp outboard will push faster than two 200's but if one 200 goes out you still have a backup. I welcome more input for sure and I'm sure others have the same thoughts/questions as well.

Dave