Picture is with HDK supplied ride height simulator used in mock up. The simulator in the longest setting simulating the installed ride height average (14-1/4") of the Qa1 DS-501 w/ 5-3/8 travel. The DS 501 extends to 17" and fully compresses to 11-5/8"
The DS-501 uses a 12" spring.
Please note how much higher in the chassis the upper shock mount is than the other brands. Also note how much shorter the control arms are.....the set-up allow the hub to be further tucked in....about an 1"