2.5 level rear end is now sagging

Hello y'all! I've been a member to TW for a while now but never had a question until now. I just had the Bilstein 5100 front level shocks installed along with new 5100's in the rear. Front is set at 2.5... my truck has the 2.7 L. I love the front end stance and want to fix the rear now. What do you guys recommend I do?
Also I had the K02's in 275/65R16 installed and have a vibration when I hit 50 and it stays the same as I speed up. Has anyone else suffered the vibration problem or should I have the tires Rebalanced using a road force machine tire balancer.... Im not sure if the shop had a road force balancer. This shop is experienced with upgrades, I really didn't drive it until after the shop closed, yes I will be calling in the morning about the issues, but would like some advice so I can be ready when I call.
maybe this is normal with the tires.... when I picked up the truck it looked even but after I got home I noticed the rear sag.
Any advice is greatly appreciated