Rear Leaf TSB on DC LB non TRD

Hey Guys,
Having the rear leaf TSB done next week. Dealer was more than happy to order it for me and called today to let me know its in. A couple questions:
1. Should I have the Billstein 5100's installed first? I plan to do all 4
2. What is the benefit of installing the rear Billsteins? Strictly for performance or will it change the look at all?
3. If I install the fronts and set them at 1.75" am I likely to have issues? I do a lot of highway driving and dont want any vibrations/drifting.
Thanks
I will post pics once its done

 

I would just wait til after. Might as well do the rear. It's easy an it's a better shock. 1.75" would look great. You shouldn't have vibes.