Don,
If you want to change all arrow sizes at once, first go to Organize - Custom Selection. In the Custom Selection Dialog Box first pick Select Only then click Criteria. In the Criteria Dialog Box chose "Arrow Style" - "Is" and the style you are using. Click OK. This should select all the arrows of that style.
Now go to the Attribute Palette. Click the button in the lower right coner and scroll down to edit. Set Arrow Attributes Dialog Box appears. You can edit the size by changing the length.
Mel Barker
Highland Drafting, Inc.
http://highlanddrafting.com