I tow a 6k lb boat a dozen times a year and have no issues with my Duratrac’s with normal inflation. Size is 275/60/20. I do have a leveling block in the front only. All other suspension is stock. When it’s time for new shocks, I’m planning on The Billstein 5100’s. I hear air bags are helpful with sag, but I don’t have too much of an issue unless my bed is full and the boat is loaded, then it’s slightly leaning back, but still tows great. Probably something to do with the 6.2 under my hood too... it’s a crew cab 6.5 box if that matters either. Sent from my iPhone using Tapatalk