Are ss rear shocks shorter than LS?

 

No, they should all be the same size, what gives the ride its height is the springs. If you are looking to drop your car if you have a LS you can get SS springs to drop it a little bit (around 1 inch) or you can get aftermarket drop springs to srop it way more than that to get ride of 4x4 status.

If you are shopping for shocks n struts go with kyb if u are an LS since they are the best bang for the buck option , or upgrade to TC suspension if you have a LSJ...