Here is a question for you and I don’t think I’ve seen an answer yes. How old are the springs and How heavy is the car? I have sold well over a hundred pairs of those springs in the past and have gotten tons of feedback from follow racers. On a heavy car (3500lbs and over) I would see mid 10sec cars start to slow down after 250-300 passes. NOS and trans brake cars a little sooner.
The older springs…springs built in the 2001+/- and older would last longer than the current springs.
Removing and playing with the clamps did change things around. More clamps on the front and less clamps on the rear would plant the tire more but soften up the hit.
Last but not least a fun fact for you all. When these springs were being designed and made for the Super Stock Hemi Dart and Cudas. The leaf spring pads on the diff were rotated different degrees from left to right. One side the pad was set 2 degrees down and the other side was set at 6 degrees down. This kept the springs from being preloaded when bolting them on the car.