Cal Tracs

Are these things worth the money? Pros & cons? I'm thinking about getting some, if I do, I will get the Bars, Springs, & shocks. I'm currently running a set of worn 340 springs & a longer shock, OEM NAPA replacement. Up frt are 318 t-bars & 90/10 shocks bestET [email protected] Average [email protected] Best 60ft is 1.57, average 1.65. The car weighs 3360 with driver. I run M/T Street radials, P255-60r-15. The car hooks up the majority of the time, but somtimes in the later rounds (5th or 6th) It will spin without warning, this cost us a couple of wins. Looking for opinions.