Short answer, no.
The hard drive is tied to he motherboard. If you move the drive to a different TiVo with the same first 3 digits in the TiVo Service Number (TSN), you must do a 'Clear & Delete Everything'. This will marry the hard drive to the motherboard. If you don't do this, it will appear that you can view the recordings, but when you try to play a recording, it will fail. Also, if you check the System Information, the TSN will be all zeros. And when you start the TiVo, you will immediately get a message saying a problem was encountered. I believe it is error #51. To clear these messages and get the right TSN on the System Info page, you must do a Clear & Delete Everything.