Remote copy can copy data from one volume to another if the number of bytes per track and the number of tracks per cylinder are the same between the two devices, and the target device has an equal or greater number of cylinders. The only way to copy data between unlike devices or from larger devices to smaller capacity devices is by using DFSMSdss (or DFDSS, or a comparable product) logical dump, restore, or copy functions. Although the 3380 volumes do not have the same number of bytes per track as the 3390 volumes, you can use DFSMSdss to copy data between the two unlike devices.
For additional information about DFSMSdss copy functions, refer to the z/OS DFSMSdss Storage Administration.