I'm using Pro Comp ES9000's on all four corners of my truck. The fronts are basic replacements, but the rears are extended length shocks. I had regular height ES9000s in the rear with just the shackles and body lift, but went with the longer shocks in the rear when I added the spindle and leaf springs because it looked like I was going to have issues with the rear shocks topping out. And that's with the 2 1/2" leaf springs. With the 4", I would go with longer shocks just to be safe. Just my opinion, though...