I'm going from 15 to 16 inch tires and wheels plus a 2 inch lift of my spring brackets. Having a dually long bed really is a challenge because they ride so high...and it takes a lot of weight to push them down. My max tongue weight on this 5ver is only 1500 pounds which is a fraction of what it takes to even engage the overload springs... I pulled this rig out of AZ last fall and found out real quick how close it comes to hitting the rails...scary really. I'm working on getting a level ride but having a lot more space between the rigs is ultimately my goal so I can rest a little easier....a flat bed would be the cure all but nothing is off the table. You never know...lol.