So I started replying to this on another thread, but figured I'll reply here as well. Since a lot of people are running this setup and this question comes up a lot, it will be good to have as many eyes on this as possible.
Bilstein is using my 4Runner for some development and outfitting it with the 6112/5160 combo. Mine has KDSS, and I've been told they're updating their install instructions for KDSS 4Runners.
During the process, they've found that the front left spring on KDSS 4Runners is slightly shorter than non-KDSS. The springs are NOT the same. For KDSS 4Runner, no offset is needed. On my 4Runner, they set the rings at the highest setting on both sides. As a result of no offset, KDSS 4Runners can have a total net of 2.9" of lift vs the 2.5" of lift on non-KDSS 4Runner.
The springs they've installed on the 5160's are prototype Eibachs. They match up perfectly with the 6112 setup up front. There are 3 different configurations of the spring: 1" lift, 1.5" lift, and 1.5" heavy. The "heavy" springs are designed for rigs that are loaded down with heavy mods/armor. Bilstein is looking to release them soon, but date is TBD.
I'm planning to get some aftermarket UCAs, but they didn't have any issues with stock UCAs.
Wheels: 17" SCS Matte Dark Bronze Stealth 6. Tires: 275/70/17 BFG KO2s.
Here's the lift at 2.9" front, 1" rear.
Here's 2.9" front, 1.6" rear.
I'll try to answer questions as best I can. Please bear with me if I don't know the answer, as the 6112/5160 setup (and 5th gen 4Runners) are new to me.
If anyone is wondering about my join date and post count, needless to say, I'm a long time lurker. I had a 2000 4Runner, but posted mostly on Yotatech. I'll be posting and getting more involved here at T4R.