Porsche 924/944/968 rear ride height can be lowered (in most cases) by approximately ¾" using the following procedure. This adjustment was originally designed for factory ride height settings across the rear of the car.

Procedure:

1. Lift vehicle SAFELY!
2. Remove wheel(s)
3. Scribe lightly OR use paint to mark the current location of the Trailing Blade.
4. Loosen the 24mm Mounting Nut (pivot).
5. Loosen the 24mm Eccentric Nut.
6. Turn the 36mm Eccentric Bolt (bolt B) in the appropriate direction to raise or lower vehicle.
   1. 1 degree of change = ~5mm of change in ride height (compare against original location)
   2. Moving the Trailing Blade up lowers vehicle ride-height.
7. Torque nuts to spec.
8. Replace wheel(s).
9. Lower vehicle SAFELY!

Notes:

1. In the picture, the trailing blade is at the highest possible setting (lowest ride height).
2. Maximum realistic range is ~4 degrees (~20mm or ~3/4" actual ride height)
3. Some folks recommend unloading the sway bar (remove lower drop-link bolt) prior to making this adjustment.
4. Once lifted and lowered, the suspension may need to be driven on for a brief time in order to accurately gauge the results of ride height changes.
5. Measuring ride height should be done from a common point in the suspension... not at the fender wells.  A common point of rear suspension measurement is the center or bottom of the torsion bar caps.
6. Most US models came from the factory with positive rake set to the rear... this is due to US bumper height restrictions.  The top edge of the bumpers were set to: 522 +/-20mm Rear, 526 +/-20mm Front (533 +/-20mm for S2).

Illustrations:
 

Application:    78 and later 924, 944, 968

Tools:    24mm socket or open-end wrench, 36mm open-end wrench.

Torque:    180 ftlbs. for both

Credits:    Skip Grehan