These are the 521600 coils. Their website says 2-2 1/2" on bottom setting, which is what they recommend with the 5100's. I appreciate the advice here, I won't even order the drop kit. It was my understanding that it was one of the things to change if you're going to mess with factory height settings.
Upper control arms.
Ur alignment may not go back to factory spec at 2.5".
3" and the tech def wont be able to get factory alignment without aftermarket upper control arms