I just installed the Rough country rear drop shackles on my 2020 Sierra AT4.
I usually do this because i am 6’ 1” and when sitting on the seat with my infant behind me, i had the seat reclined all up on the car seat. So, when leveled, the seating position is more relaxed and upright in my opinion.
I figured i would show it since it was really hard deciding if i should do it since i couldn't find any AT4 with it done. I have it set to the 1.5 hole.
The shackle kit from Rough Country comes with a 1” and 1.5” hole.
I have had it like this for 3 months now and i still dont have any vibration coming from the rear.
I haven't measured it but it looks alot better. The rear sits like 1/2 to 3/4 higher than the front. Which is nice.
The very top is before the kit was installed, the bottom 2 are after the install.