Been using them for 5 years now with SS springs on my Dart Sport. Very consistant 60 foots, 1.40-1.42. Just using Monroe shocks on the rear, the bars in the lower hole. I set the preload on the bars with my weight in the car and have had no problems. Car weighs 3290 with me in it, and a small block pump gas motor, with 904 transmission and 4.88 gears.