Hotchkis 80390 TVS System, Stage 1, 67-72 C-10 Small Block, 4'-6' Drop, 2WD - Manual (Page 37)

New hardware is also provided for the upper mount. The Hotchkis upper mount has 2
adjustment holes. The hole toward the rear is the stiffer shock setting. Once the
shock is in place, fully tighten all shock hardware.
Lower the lifting jack from the trailing arms and you are now finished with the rear
shock installation.
Installation of Hotchkis Track Bar