Originally Posted by KamiSpeed

they don't require but you should definitely get the car re-aligned, and a rear toe kit is also recommended but not required, if you re-align you can get the suspension close enough to stock alignment that nothing else is required. If you want to read more up on this check out this thread, its a lot of info but its all useful if you want the springs:

http://www.the370z.com/brakes-suspen...-reviewed.html