They can be a pain to set up, even more so with the adjustable damping and rebound ones i have. The rear took me about two hours just to match the damping and rebound up in pairs, theres no indents infinately adjustable off the car, thankfully front top adjustable.
For ease take a measurement how the car is now on the flat.
Set up front and rear in pairs ie exactly the same adjustment and mark it some where with an ink marker.
Slap em on car see how it sits bear in mind it will take at least 3000 to settle, 10k even better. Undo locking ring and rotate each shock so it matches in pairs ie 1 rev, 2 revs etc. Mine is 1mm rise per revolution 1mm pitch.
It will be a very fine balance, too low it will bounce and bottom out, its trial and error but easy to do on the rear without a jack.
May find on a run they get a slight bit better or worse as the gas warms up, never noticed it on the standard Sachs oil filled originals though.
Worst shocks ever had were Spax top adjustables on an XR2, no rebound bounced every where. Best Koni top adjustables on two XR4X4 turbos smooth but firm.