You may want to fit a steering damper if you raise the rear, these bikes already have small trail numbers {under 4 inches} and raising the rear will make that even smaller, making the steering quicker and increasing the chances of head shake or tank slappers...
Raising the rear is common on early race bikes but i am yet to see one without a damper, i have had some serious tank slappers on standard bikes so i fit dampers to all my old Honda's. Just saying.....