Better to do something like
3dWarp -matparent XXX+orig -prefix func02rot -cubic func02+orig
where XXX is the prefix of the file output by 3dWarpDrive. The (relatively new) "-matparent" option to 3dWarp will read the matrix used by 3dWarpDrive directly from that file, and use it to do the transformation.
As always, a visual check to make sure things worked decently is a good idea.