Wilwood Low Profile Disc Brake Kit Help....

Hello to all. Getting ready to order my rear disc brakes and I'm having a bit of trouble understanding the Wilwood install instructions. I'm trying to determine how far outward the brakes will push the wheel. From what I can gather, it appears that the snap ring goes against the rear end housing and the brake backing plate goes against the snap ring and then the bearing retainer. It looks like the bearing retainer is stepped to accommodate the bearing but if the retainer is going against the backing plate, what's the use? Anyone use a similar kit that can clarify please? No pictures or videos I've seen are very helpful. Thanks for your help and Merry Christmas!