It "might" be possible.
You see it depends
The camber shims on the upper ball joint will be maxed out with the spacers regardless of lift.
the easiest was yo explain it is like this.
You can add the F-150 spring seat (1-5/8" lift) to a stock truck no problem. However say you order a James Duff 3" lift, it comes with a 3" coil and a 2" axle pivot drop bracket. Even though they call it a 3" lift, only the coil is 3", everything else is 2" so your camber shims will already be near max, adding the coil spacer to this will not work.
So if the Superlift 5.5 system comes with a 5.5 coil and a true 5.5 drop bracket (without measuring I bet it's a 4" drop bracket) it would work only with a true 5.5 drop bracket.
So in reality I doubt it, why because currently I am running a 3" coil with a 2" drop bracket and the spacers, my truck cannot be aligned. This forced me to make my own bent beams to correct the problem so I dont keep eating up tires, either that or settle for less lift or new weaker drop brackets.......
Make sense? or did I just make it worse?
Different lift kits have different drop brackets/dimensions. The camber is only flexible to a point, beyond that you will not be able to align......