Anti roll bar?

My car did similar body roll years back. I added the anti roll bar to my car it made a world of difference on how much smoother and more consistent my car launched. Mine is a 4 link rear suspension.

We just put an anti roll on a roadrunner over the winter that has ladder bar, housing floater, and Calvert split mono leaf. It also made a huge difference on his car. Car is much smoother, has less traction issues and is much more consistent on the starting line.