The leaf springs will last longer with the help of an adjustable snubber especially if you have slicks, power and a little traction to start with. When adjusted correctly they help plant the tires when you hammer it. The first mopar I raced alot had HD springs and no snubber, ran mid 12's and developed a nice air gap between all of the leaves just outside of the U-bolt-clamped area. Now I use the snubber.