To answer your question, NO the KS chest/back is NOT larger than the SC. However, the KS drop boxes are the largest out there and are not even close to accurate. The KS bells are large and wonky while the forearms are the smallest out there. The KS biceps, belt (it's a one-piece) and knees are the best part of the armor. I own a KS setup and have replaced all of the offending parts with SC or other armor bits.