In sage mode alone, Naruto was able to lift a stone statue of at least ten times his size (or weight, at the very least because stone is more dense than most of his body). With KCM, he struggled to hold fairly large stone bricks without crushing them. He is now sage mode, KCM, and Ashura chakra with all bijuu's. He could easily lift 500 tons with his two normal hands. With his hands and KCM hands, he'd probably be able to carry much more but the only issue is that the intense weight would severely damage his body.