I grew up racing leaf spring cars. We raced first gen Camaros in NHRA Stock and Super Stock and never changed rear suspension. In fact, we always ran Lakewood j-hook traction bars and the cars left with the wheels in the air. But that was before John Calvert created the CalTracs bars, and the leaf spring world would never be the same again. Sure, there are some other brands out there with slight differences, and many copycats, but Calvert is who changed the game in the first place.
And nobody in their right mind believed that a leaf sprung car would go as quick as some of them have over the years, but as simple as these systems are, they do require some smart modifications to make sure parts will live with big power.
Check out Ron Rhodes video below where he goes into what they run and why on their Camaro.