Change Flash Builder Default Src Folder Name?

I know you can change Flash builders default "Main source folder" by right clicking on the project properties and going to the "Flex Build Path" ...but how do you change that by default for all new projects? I prefer the folder name "src_flex" rather than "src" when I create my projects.You can do this for PHP in "PHP>>New Project Layout" preferences but I don't see anything similar for Flash Builder or know if there's a (hidden) file I could edit to do this.