What's a center link? When you changed the bushing it caused the toe-in to change; your left and right wheels no longer have the same toe and camber.
The bolts that go through the bushings, do they have an enlarged oblong shape at the head of the bolt that fits into the oblong shaped hole in the frame, or do they have a grove in the threaded portion of the bolt? The bolt with a shank that is oblong shaped and fits into a similar hole in the frame is used direct from the factory.