Multiple reboots after HD restore

The expanded HD in one of my Premiere's died a few days ago. I saw this coming so I have both full and truncated backups as well as a clean image from here.

I restored a truncated image to a new HD (same model HD) and gave it a try. After several boot cycles, it booted up. After connecting to network, it said it was "pending restart" so I figured there had been a sw update since I made the backup last year. After that, it cycled through boot for several hours, one time saying it was installing an update. Eventually it booted and worked fine. However, if it tell it to restart, it goes through the boot cycle for an hour or more before eventually coming up. I have repeated this process about 5 times, thinking it may be rebuilding something when it does this.

Any suggestions on how to address this?

I also have another Premiere and have now made a full backup of the HD from that one. I did put the HD from the second machine into the first and it booted w/o issue. I have not yet tried the clone HD in the original machine as it made it over night.

Final question for now. The HD from the 2nd unit is much smaller than what I had in the first but it is not the original and was expanded many years ago. Is there a method to take advantage of the larger HD or am I stuck with the size of the HD I am cloning? I do actually have the original HD but I have read that trying to start over with that may fail due to all the sw updates since then that it may or may not be able to get.

Update: I put the cloned HD from the other TIVO in and it booted perfectly. Since that Tivo is on a cable card and the other is not, I told it to do a complete erase and now it is cycling through the boot sequence endlessly as well.

Thanks for any input.