I have them on my Tundra. I had a fifth wheel, pin weight 1050. So I added the Super Springs. Advertisement said it would raise the rear one inch, I got almost three. So much that I had to add 1 1/2 inch front lift, which actually gave me over two inches of lift. Long story short, it was level unloaded, maybe one inch of front pitch, and my fifth wheel squatted my truck two inches. Sold the fifth wheel, bought a Jayco bumber pull, which is or was supposed to have 650 pound hitch, and I am squatted two inches maybe three. All I can figure, 5th wheel over axle, trailer when hooked up is over a foot from bumper.
I wanted air bags way back, but you could not buy a set for a Tundra with a fifth wheel hitch on the mid size bed. I am to tight to add bags on top of super springs.
The S.S.'s were an easy install is about all the good I can give them.
And after I bought the S.S.'s, but hadn't installed them, I hooked my 5th wheel up and my Tundra barely squatted 2 inches with stock springs. But they were paid for and I didn't want to ship them back so one thing led to another!