I should have told you where I read that in the first place :). It's in your online docs here: http://www.telerik.com/help/wpf/radchartview-series-pieseries.html
The text in question is the top of the second paragraph:
"The pie series can be customized with the following properties: LabelOffset, LabelTemplate, AngleRange, ShowLabels and RadiusFactor properties. LabelOffset determines how far from the center will the labels be positioned. "
I want to move my pie labels from the edge of the pie slices to somewhere between the center & the edge. I though that property was what I needed.