New Spanned Volume is Grayed Out/Not Available

[swingking03]

I have two drives (Disk 3 and Disk 4) that I recently formatted to remove all contents and would like to create one large spanned volume with, however, when I right click on the drives, New Spanned Volume is grayed out. Last week, I successfully created spanned volumes with 2 different hard drives. Any help creating this spanned volume would be greatly appreciated.

 

[swingking03]

I was able to achieve the spanned volume by converting to dynamic, then deleting the volume on each.