A very long time ago(1976), I had a DD 69 Barracuda slanty/7.25. I was running Protrac N50-15s on 10" steel Kragar SSs. That was a heavy, heavy combo. But guess what, every single ounce of them was supported by the highway under the treads. So no problem. At 55Mph, though the body and tires would combine frequencies to drive me crazy. 50 was ok, 60 was fine. I still remember the sound; whoo-whoo-whoo-whoo-whoo......reverberating through the cabin.
BTW, Ns were huge; probably like 325s. Had to have air shocks on it, cuz the treads were pumping air on the outside of the wheelhouses. I was 23.What the heck did I know. But man-O-man was I cool.lol