Shackles vs. add a leafs
If you do searches here you will find a ton of info on Explorer Saggy Ass Syndrome. The long and the short of it is if you like the springiness of your rear, and need lift only, add Warrior's shackles. If it needs firming up, as well as lift, add leafs.
Summit has 3 levels of Explorer brand (no relation) add a leafs, for like $26 bucks a pair, so you can't go wrong. My ass was down about an inch, and bouncing around like crazy, even with new Edelbrock shocks.
I went with the lowest level. It brought it up almost 2 inches, but quickly settled down to an inch so it is even with the stock front. The ride is now fine, not firm at all, a little on the soft side even.
If I towed, or wanted more height, I would get one of the higher levels. You will have to remove the rear shackles to do the job anyway, so if you want even more height you could add the longer shackles. I personally never liked the looks of shackles, but I'm nuts.