The latest, definitive word on the SA180 mod is right here...

http://www.knifeforums.com/forums/showtopic.php?tid/821501/post/1516203/hl/

You can get the three-step (or even the four-step) pulleys and modify them yourself, but I decided to pay the big money and ordered the kit from Bearing Service & Supply and with the write-up above you can't go wrong.