the dia is much smaller then stock. short ver. cut the big perch off and put a lip lower on the housing and add ground control adj sleeve over housing then add the ten inch spring and mount... now you can lower or raise car to the height you want it...
most places only sell in set of four and go for around a grand + or - if you use norm strut of adjustable ones...
MSA
Victoria British
Ground Control and other places sell them...
most of these places sell the Tokico Ilumina 5 way struts for 149 each the nonadjustable go for 72 each... KYB are about 50 each... stock spring rate is like 165#
I got my front only pair for 480 with shipping from fonebooth.com Mike is great to work with.... he sells the ground control, hyper coils (Powder Coated), and Tokico struts cheaper then anyone else I have found... the 5 ways for like 125 each... he also sell Outlaw brakes BTW...
I got ground control with 200# hyper coils and the Ilumina 5-way adjustable struts from him... shop around but check with SCCA/Mike (handle on hybridz.org) before you buy...
here is one long post from hybridz about coil overs to read...
http://www.hybridz.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=6&t=000310
Here is ground control home page also...
http://www.ground-control.com/
Z U V8ter