Okay, you must be on the i747M from one of the Canadian or Mexican providers.
That doesn't indicate the bootloader. If you never put a custom ROM on the device it should be the same as the baseband(modem) and ROM version. You can verify the bootloader with the
"Samsung Info" app from the PlayStore or from Terminal Emulator if you have one installed. In the terminal window enter
If the bootloader is indeed the same as the baseband you need to upgrade to MK5 bootloader and modem to meet this ROMs requirements. enewman17 posted a
download link for the MK5 pair, give thanks to him for the file. Or, you could go to
sammobile and update to the stock rom for your device before flashing Dandroid ROM. Going the stock ROM route would probably clean up the internal storage more thoroughly than only flashing the bootloader and modem. At the sammobile site there is more than one MK5 rom available, they are sorted by carrier. I know some of the carriers share firmware, but I don't know if all do.
If you want the newest bootloader and modem, then you just continue the process going from one pair to the next for your carrier. The carriers seem to be splitting on which version is next. After MK5 you have ND2 or ND3 depending on your carrier. Likewise there are more options for the 4.4.2 bootloader and modem, depending on carrier.
Once you have upgraded your bootloader and modem, flash the ROM in accordance with the instructions in the first post of this thread. BTW, you may want to take the opportunity to sim unlock your phone before upgrading from 4.1.2. To do so will first require downgrading to 4.1.1, look for the free unlock thread for instructions.
The latest version of this ROM is posted in the first post of the thread. Danvdh has one other ROM for this device, it is also based on android 4.3. It is called DanKang and was posted to the forum a month before this one was.
HTH.