I did a search and did not find what I need. How long to change the front and rear springs. Is there a procedure posted?
Car is a 01 and I want to install Z06 springs.
Thanks

 

I'd say, first time, plan on a day. (Can be done in 2 hours once you've done it) Look in the C5 tech area for "lowering", it's 90% of the procedure. Here it is in writing just in case.

Front:
After removing wheels and setting car on jack stands

1.) Remove bottom shock bolts (13mm deep socket on bottom, 13mm box wrench on top)
2.) Remove Upper A Arm nut (underneath upper A arm) (18mm)
3.) Remove 1 end link bolt that is attached to Lower A arm (18mm)
4.) Place jack under Lower ball joint right behind brake rotor (to hold it up)
5.) Smack (gently, rubber mallet) upper A arm to release it off ball joint (the nut you removed in step 2
6.) Let down jack a little and wiggle out end link from lower A arm, then let jack fully down.
7.) Use a piece of wood (2x4) about 4" long and set on top of jack, end up, then Place against the spring, as close to the end of the spring right behind A arm and jack up spring to get about a 2" seperation between spring and Lower A arm (you will find you can push down on the lower A arm a bit)
8.) Remove lowering bolt between spring and Lower A Arm (8mm on top of lowering bolt)-THIS IS THREADED backwards-

Repeat on other side

9.) Remove 4 bolts on the 2 brackets holding spring (self explanitory once you see it)

Reverse procedure to put it back together.

The rear is easier: (remove wheels, get on jackstands)

1.) Put jack (with 2x4, probably laid flat this time) under spring between lowering bolt and end of carriage to hold spring in place
2.) Remove lowering nut (18mm)
3.) gently lower jack

Repeat other side

4.) Remove 4 bolts holding 2 brackets for spring

Reverse to put back together

You can also lower the car while you're at it if you want-
1.) Adjust the lowering bolt all the way up and you'll drop about 1/2"
2.) Cut the bushing off the bolt and you'll drop about 1-1/2" (leave about 1/8" rubber on it for cushion, or place a sheet of rubber down on the Lower A arm if you remove bushing entirely)
3.) Leave the bolt out and you'll get 2"

 

http://www.ls1howto.com/index.php?article=20

Words and Pics. Can't ask for better than that.