Originally Posted by Volk Z

Yes you can put the wheel back on with only the spring to check the height keep in mind that it will adjust slightly when the strut and pre-load are set but it will be within a half inch or so of that height with just the spring.

As for adjusting, i have installed BC coils on Z's over 7 times... Heres the scoop for adjusting.

Fronts- You only adjust by the single gold collar that locks the strut "fork" DO NOT adjust the upper 2 gold collars on the front as those have the stock preload set and you will have to reset preload on the front if you move these.
I believe counter clockwise lowers/ clockwise raises

Rears- For the rears once you get the desired height you will lock the 2 gold rings (seems to be usually a half inch to a quarter inch of threads that hang out from the bottom portion for a 1.5 inch drop- depends on your weight of course)
Then lower the perch and put the spring and top portion in that has the threads and gold rings and close the perch that holds them up by bolting the one large bolt that holds the spring in the perch.
Then you should have the strut installed but NOT the bottom portion. This is left off to set the preload.
** to set the preload in the rear you will get a jack underneath the perch that holds the rear spring be sure to have someone keeping a measuring tape on this while it slowly gets jacked up...You should set 1/4 to 3/8 of an inch of pre-load on the spring once you do that lock the jack in so it holds the spring in place. Now to lock in permanently you will spin the bottom fork of the rear strut until it lines up with its hole where the bolt slides through. Slide the bolt through and use the BC provided NUT they provided.

Tighten all bolts and set down... And your done.

-Chad