the rear springs installed on the Tahoe are extremely stiff, makes it ride like a log truck.
swap springs to 2" lower springs by Mcgaughty, it will ride like a Cadillac !
When I received my 2015 LT with trailer option and 20" wheels the ride was like a dump truck. I changed the fronts to Escalade springs. Had to grind out the inside diameter of each spring end slightly to fit the large diameter optional trailer shocks (struts).
I used Belltech 34324 rear spring 4" lowering kit with 2" spacers to get the correct ride height. Ride was fantastic. Then, just recently, I saw a fantastic deal on Belltech 5321 springs that give a 2" drop without the need for spacers. I installed them and they are perfect. Obviously it is better to eliminate spacers if possible so the 5321 are the springs to use to provide the best ride and also reduce the "raked" look. If you actually like the stock raised look, just use 2" spacers and still get the improved ride.
Belltech uses a progressive spring rate with coils wound tighter at the top of the coil for soft ride on small movement yet provide stronger capacity when vehicle is loaded. That is why the ride in my opinion is better than any of the other springs available.
The instructions with the 5321 springs specify NOT for use with auto level vehicles. Mine DOES have auto level and they work perfectly. You have to adjust the sensor rod to the lower ride height or naturally it will automatically try to raise it back to stock height. I bought 2 - 4" long 1/8" all thread bolts to replace the stock rods. I cut the heads off the bolts and popped the plastic sockets off the stock rods and simply screwed them on the bolts. When installing the sockets on the bolts I set the distance at 3.25" center to center of the socket. Just a slight change of that setting will raise vehicle height.
The spring kit includes shorter bump stops. I suggest you not use them unless you also install the 6651 shock extension kit that was part of my original 4" lowering kit.