This is a free method. I cannot vouch for it as I haven't tried it and obviously haven't used VB3 with it. But since it's free, you can try it yourself.
http://www.macprovideo.com/hub/logic-pro/how-to-run-32-bit-plug-ins-in-logic-pro-x
Here is an app that will convert VB3 from 32 bit to 64 bit:
http://www.soundradix.com/products/32-lives