Been waiting to sign up on this forum for a while now and share thoughts on this subject. We've had our 2023 High country 4x4 with has Adaptive Ride for a few weeks now yet really wanted to bring down the rear just a little bit to remove the rack. What surprised me was how different our truck sat compared to every other 4x4 1500 chevy I've seen posted, not sure if its the high country suspension is different than others? But there was only 1 1/16" difference if that from the front to the rear fenders to the ground. I almost drilled another set of hole since I only wanted a 1/2" drop lol. Lucking we end up with about a 1/2" rack. Do love the way it looks now, wishing I could go lower both front and rear but thats not going to be easy with this adaptive ride crap lol. Not sure how much this 1/2" lowering is really going to effects the adaptive ride or not time will tell or I wont even notice.
Regarding the whole shaking feeling most of us all seem to get when slowing down, yes its there. Wondering if it is also the torque convertor at those speeds causing some of this. Ours did it prior but it does seem a little more pronounced now (kind of livable IMHO just for the looks alone). It happens at around 27-22 ish mph when deceleration. I've attempted in different gears in L with different throttle / loads trying to understand how to drive around it or to create it more so. One thing no one mentioned that also changed when we did these drop shackles is that there is now polly bushings versus rubber. So if there was some shaking or vibration to begin with, it would only be even more pronounce now. Also the connection point between the rear left spring and the new shackle is now farther away creating even more room for defection/vibrations. Not saying any of this is truth, just food for thought that no one has mentioned. Wondering if there was a drop shackle kit that had rubber bushings instead, that it might help eliminate some of that vibration we are feeling with these lower cost kits. The concept of why it should be equal angles totally makes sense though, might have figure out how to shim it. Probably the best video explaining it.
Anyway, I don't have before but it wasn't much different about 1/2" higher in the rear. This is the first set of holes not the furthest out ones. Same kit everyone else is purchasing on amazon lol.