Significant changes to the stack were implemented in version 2013.
Documentation is at http://yoursystemip:yourwebserverport/csp/docbook/DocBook.UI.Page.cls?KEY=GCNV_R2013_1 (Cache 2013.1 Upgrade Checklist)
Short story - $System.Util.GetFrameStackSize() will tell you what the configured stack size is.
$System.Util.SetFrameStackSize() will let you change the stack size for all new processes
$System.Process.FramStackSize() gives the stack size for the current process.
Mark