Can a hard drive from a Premiere 2-tuner be simply dropped into a Premiere 4 box?

My friend has a TiVo Premiere 2-tuner model that I upgraded for him a couple years ago with a 2 TB hard drive. I was thinking of selling him a Premiere 4 that I have and was wondering if I can simply transplant the hard drive from the 2-tuner to the 4-tuner and have everything retained (shows and settings). Thanks!