MP 1,1-5,1 Upgrading to Mojave on a flashed 4,1- are there any precautions necessary?

[BrickBusterz]

Hey everyone,

I bought a firmware flashed Mac Pro 4,1 (Early 2009) off of Craigslist last week that is running High Sierra 10.13.6. The previous owner installed a Xeon W3670 and flashed the computer's firmware to 5,1 firmware, and I bought an RX 580 to allow me to put Mojave on it. However, is there anything else I need to do before running the installer or am I good to go? I figured I'd might as well ask before my new Mac Pro becomes an aluminum bench. Thanks in advance.

 

[Macschrauber]

Make a Firmware Backup with Romtool, google dosdude romtool, password is rom just in case, upgraded 4.1 Roms are sometimes a bit messy.

Make a nvram reset

Read https://forums.macrumors.com/thread...-bootrom-upgrade-instructions-thread.2142418/

At least the 1st post