What you are calling the center link is also the toe adjustment. That is adjusted at the outer ends where it connects to the knuckle. When you changed out the lower control arm the new bushings were stiffer than the old and that pushed out at the bottom the knuckle, thus changing your camber and because you only changed one side it changed the toe on that side also while leaving the relationship to the steering knuckle on the other side of the car unchanged. Basically, you have one side of your set up different than the other; thus the car pulls to the right. You may think it should all be back to "normal" because the new control arm has new bushings, but that has changed from what your alignment was set at and thus the two side of your car are now different in it's alignment.

The outer end of the center link, the tie rods and ball joints can be bought separately.