I would normally say to make a Hexen disc, but since your drives aren't working, your other options are to make your new drive using a PC, or hooking up your new drive to one of your Xboxes in place of the DVD drive and using the app Chimp to format the new drive.
If you have a way to hook up your new drive to a PC, you could use something like XboxHDM to build your new drive. There's newer versions that run from Windows 10 and work with drives connected through a USB adapter (ability to lock the drive after may vary). This method can be tricky if you haven't done it before.
The easier route, and probably the route I'd recommend, is using Chimp. In a nutshell, boot up your Xbox, then load into Chimp. Then unplug your DVD drive and plug in your new drive and continue in Chimp choosing the correlating menu options for formatting and locking the new drive.
https://github.com/Rocky5/Chimp261812. This method copies whatever is on your C and E drive from your SOURCE Xbox, so keep that in mind if you plan on dropping your new drive into a stock Xbox (your source Xbox may or may not have the softmod files present on your C and E drives because it's hardmodded instead).
To lock the new drive, you'll need a backup of the EEPROM for the Xbox it's going into. An alternative method to doing that is to null your hard drive keys on both Xboxes, then just lock the new drive using your hard-modded Xbox. Since the keys are the same between the two consoles (they're both set to all zeroes), locking a hard drive on one will allow it to work on the other.
P.s. your post says Xbox #2 is TSOP flashed. You can't TSOP flash 1.6 consoles. On 1.6 boards, the BIOS was embedded into a different chip to prevent hacking. You probably mean that it has a modchip.