As an added comment, I just went through this with Tokico HP shocks and Steeda springs on an 02 mustang V6.
I bought the cc plates through American Muscle and the information that was contained with the plates from Maximum Motorsport was very enlightening. Go to their website and do some reading.
Also, go to Miracerros.com and read his advice. Finally, one bit of advice that none of the installation instructions talked about was getting the new springs in with the American Muscle isolator bits that I installed. You have to pry the old ones out and that is covered. But to get the new ones in, place them in place top first, then lubricate the bottom with a spray lubricant on the a-arm where it sits...it has to go over a rise that the spring sits in. Lubricating that area, will allow you to pop the part in without issue. I was surprised when it just popped in after some had dripped down from the top where I sprayed first. Took me about 4 hours for the driver's side with the CC plates from Maximum Motorsports and about an hour for the passenger side.
Miracerros has several installation instructions cited and also gives you some technical data on drop rates for various manufacturers of springs. Very good information. I downloaded several installation instructions. Actually American Muscle has several very good installation video's and written instructions as well.
Alignment was almost spot on. Car handles great and this is from a Corvette/RX7/Miata perspective. As for length of time to install, take into account I did this by myself and am not in my 20's or 30's anymore