Thank you both for clarifying this issue.
Jason, I made an observation, not a negative criticism of the coils or your post.
I run 862 in the rear, no third row, no OEM tire carrier, but a heavy Sean-built rear bumper with a 33" spare on it.
It is a rough ride, but I like stiffer suspension setups since I hate body roll during turns.
Seeing the rate of the rear TD brought up a visceral reaction, thinking about how the car would run empty or near empty.
A rate of 320 lb would rattle my brain pretty good. I wouldn't go that far with my setup. Nothing more than the current 260 lb rate would make sense in my case. It is very rare that I load her up with people or "stuff".
The reason I asked initially was regarding my curiosity about an even softer spring rate. I am at a point at which I am debating if my stiff suspension makes a lot of sense according to my driving habits and needs.