Lower control arm sway bar tabs not the same height
If bias is present the end links can be shimmed by adding a sleeve spacer, or making one shorter. When connecting links you will discover if they need to be shimmed for balance.
For certain conditions bias is desirable, if in the correct manner. I would think a rear bar could be shimmed for drag race to improve load transfer.
I shimmed the bar on my 2.2L Omni turbo 5/8" to get more traction, the improvement was significant, without a detriment in handling.