I’m not sure what’s going on with ST but seems like they aren’t getting spring rates right lately. I’ve heard the same thing from a few people. Maybe just a formula they are using going off of something that has worked in the past and not actually doing them on the cars. They did springs on a rzr I had years ago and they were spot on but a buddy of mine that did their kit on an xpedition had the same issue as you. Not sure how much preload he ended up with but it was quite a bit more than had they suggested.I know shock therapy calls for measuring ride height loaded and with driver/passengers. I gave them heavier weights than I typically run and still had to put in 2” of preload to get to my 15” ride height (32” tires). Don’t love it but not sure what else to do. Hope you like the schmidty kit.