I will add 2 cents here. I put 6 leaf Espo plus 2 springs on my Duster to keep it raked when setting torsion bars at just above factory ride height (2” difference from bottom of pivot to bottom of ball joint on lower control arm). All front suspension is rebuilt. On front I run 215/65R15 at 26” tall and have no rubbing issue. Out back running 255/60R15 at 27” tall and from rear of front wheel well to front of back wheel well is around 1.25” gain from front to back. Now before you think I got wrong leaf gain or something, my other factors are that the front torsion bars are cranked to about 1/8“ above factory, with max height tire that fits in front wheel well. But the real story is the B-body rear axle that the spring perches were welded on at the wrong angle by prior owner which required me to use 6 degree shims to correct pinion angle, that lost 1/2” of lift in the back… had I gone with a +1 spring my ride height would be close to level front to back, no rake and stock +0 spring It would be squatted. So remember all of these factors add up, from tire size to torsion bar adjustment, but the pinion angle is the sneaky one that will start killing your ride height if you need shims to correct it, or live with a vibration. I lost 1/4” height changing the 3 degree shims to 6 degree shims this week to chase a vibration out of it. My pinion to driveshaft angle with 3 degree shims rotating it upwards was about 7 to 8 degrees, now it’s down to 2 to 3 degrees with the 6 degree shims in there, and another one of my vibrations is now gone. I know this is a long post now but this is all details that affect springs… and you must calculate accordingly with your front end on the tires and ride height you want first, and then your rear tires you want to run need to be present as well. after that I would go with +1 more than you think you need in case pinion angle needs to be adjusted with shims. Good luck.
