my 65 is backhalfed and i have cal trac's.when i bought the car it was a cobbled up old race car.the frame rails were sawed in half to make room for the 14x32 tires.it was a mess.so i backhalfed it and put 33-21.5 mickeys on it and put leafs on it beacuse i wanted to street drive it.looking back i wish i would have put a 10.5 tires and a ladder bar on it.it has never sixty footed as well as it did with 002-003 s/s springs.but it is way more consistant in the sixty foot with the cal-trac's.with the s/s spring it either hooked or spun.even on a marginal track its never more than three or four numbers off with the cal-trac's.