Inventory Conversion - Raw Materials only

I was wondering if anyone has ever been through an inventory conversion
with Vantage?

We went live two years ago (on 8.0). Against all levels of my
recommendation, we carried over the part numbers from our legacy system.

Now (8.03) they want to restructure the Part Number to be some what

Has anyone done this? If so, how did you do it?

Thanks in advance for your responses.
Patty Buechler