That's how rear lifts are done, but blocks come in the kits, see the part on top the iso mount (under the spring) in your pic? You will need something like that or another set of shock mount plates and blocks, also how are you going to lift the front?
couple other ways to lift the back..
http://www.frontiernet.net/~irishhills/rearlift.JPG
http://www.frontiernet.net/~irishhills/rearlift2.JPG
You will also have to trim the rubber in the iso mount to clear the pin on the axle, when you flip them.