This is my first post, and i cant seem to find any info on this specific question, albeit i have found 'similar projects' with different applications.
What i've done is prepped cabling and connectors to use a 3.5 inch Western digital caviar blue with my 360 slim. I'm in the process now, of fashioning an enclosure that matches the system, but so far, I've already made a connector cable and used the board from an old IDE enclosure to draw the needed 12 volts from a separate power source. Im trying to do this using materials i already have on hand, to avoid spending my family's cash, and i have a surplus of 320gb western digital desktop drives and old enclosures Atm.
I know im already halfway finished, but i figured i could try and receive some input, on wether this could work, if anyone else has already done this (and why it's so hard to find)' or if i should just hit it with a hammer

Shouldn't the logic boards from a particular manufacturer use similar chipsets anyway, making the bin files possibly compatible?

you need to get the drive into vendor mode to modify the firmware on the drive (Just like with DVD flashing) if the same commands are used to put the caviar into vendor mode as the scorpio then it should work.I

since it is an extra drive I say why not try worst case you kill your drive, best case it works, or the drive just fails to enter vendor mode.

Slow going on it, but I'm getting there. I have to see if it's a similar process.