I have heard of high HP cars bending springs at the cross bolt with cal tracs. That's one of the reasons I went with assassin bars plus theres more adjustability. They are very nice! I also went with smiths spring perches for them. Along with calvert split monos and sliders.

67 Barracuda, 470" B, Glide, FuelTech FT600, Precision, Ptc, QA1, Calvert, Smith racecraft, Afco, Dana 60. 275 radials