flipbook printer is designed for this - you can customize nearly any imaginable layout.
(ps. make sure you download the latest beta version posted in this section - it has special features designed for handling big books and multiple copies of books).
you configure your card stock from the appropriate tab, then print out a test page (shows you boundries) until you get it right, then give it a custom name (like IndexCards3x5) and click the save icon.
when you get it right, upload the config file here (find it in your flipbook printer cardstock subdirectory) and attach it to a post in this section so others can use it
let us know if you get it to work!